actors Influencing Yield, Color, 
Size and Growth in Apples 



A THESIS 

Presented to the Faculty of the Graduate School 
of Cornell University for the Degree of 

DOCTOR OF PHILOSOPHY 



BY 



JOHN POGUE STEWART 



[Reprint from the Annual Report of The Pennsylvania State College, for 1310-11] 



Factors Influencing Yield, Color, 
Size and Growth in Apples 



A THESIS 

Presented to the Faculty of the Graduate School 
of Cornell University for the Degree of 

DOCTOR OF PHILOSOPHY 



BY 

JOHN POGUE STEWART 



[Reprint from the Annual Report of The Pennsylvania State College, for 1910-11] 






\> 



e*° 



jH»*6* 



- No. 20. THE PENNSYLVANIA STATE COLLEGE. 401 



I ACTORS INFLUENCING YIELD, COLOR, SIZE AND GROWTH 

IN APPLES. 



BY JOHN P. STEWART. 



INTRODUCTION 

The following paper is essentially a record of experiments and 
observations bearing upon the subject above, in which (eppecial 
emphasis has been laid upon principles and the present apparent 
reasons for the particular results secured. It is based chiefly upon 
work started by the writer in Pennsylvania in the spring of 1907 
and maintained continuously ever since. Relevant observations and 
experiments elsewhere, however, have also been introduced wherever 
they seemed to throw light upon the particular problems involved. 

Since principles and causes have been uppermost in our present 
treatment, more than usual attention has been given to preparing 
the way for the discussion and interpretation of results. On this 
account, approximately the first third of the paper is devoted to 
what may be called preparatory matter, some of which may seem to 
have only remote connection with the particular questions at hand. 
In most cases the connection appears, however, in the subsequent 
discussion, and it all remains as a fund of description and general 
facts to which we may refer later, and upon which we may be able 
to draw in the explanation of new and possibly unexepected phe- 
nomena. 

General Status of the Apple Industry. 

Among the fruits of America, the apple is by far the most largely 
grown. According to recent reports of the census, with reference 
to yield and number of trees, the apple far surpasses all other tree 
fruits combined. The exact extent of this excess may be seen in the 
following tables, I and II. 



26—20—1910 



402 



4NNUAL REPORT OF 



Off. Doc 



Table I. — Production of Fruits in the United States in 1889, 1899 
and 1909; and Number of Trees of Bearing Age in 1890, 1900 
and 1910. 

(As reported in the Eleventh (1890), Twelfth (1900) and Thirteenth (1910) Census). 





1890. 


1889. 


1900. 


1899. 


1910. 


1909. 












.. 








m 
















Sf 




bo 


£ 


Kind of Fruit. 1 


earing 




be 

a 


S3 

s 


a 


OQ 

3 




J3 

o 


a 
o 

o 


O 


a 


,0 


a 
o 

o 




'& 


•a 


fJQ 


3 

•a 
o 


to 


3 

•a 




a; 




50 


£ 


o 




S" 1 


2* 


&H 


w 


h 


fi 



Apples, 

Pears, 

Apricots, 

Cherries, 

Peaches and 

nectarines. 
Plums and 

prunes . 

Totals without 
apples. 

Ratio of apples 
to other fruits. 



1 ! 

120,152,795 143.1 05. fi£9 ! ail.V&i. 7*U ! 17S .SO/T.esm 


151,322,840 
15,171,524 
3,669,714 
11,822,044 
94,506,657 

23,445,009 


147,522,318 

8,840,733 

4,150,263 

4,126,099 

35,470,276 

15,480,170 


5,115,065 

1,582,191 

5,638,759 

12,601,129 

7,078,191 


3,064,375 ' 17,716,184 fifiSS .417 


1,001,482 5,010,139 
1,476,719 11,943,287 
3,561,042 i 82,200,414 

2,554,392 | 30,780,892 


2,642,128 
2,873,499 
8,807,186 

8,764,032 


32,015,325 


11,658,010 


147,650,916 


29,712,262 


148,614,948 


68,097,543 


3.753 


12.275 


1.366 


5.903 


1.018 


2.167 



1 Table I, is from Table 3, part VI, pp. 700-701, of the 12th Census Report, and from advance 
bulletins of the 13th Census. The totals and ratios have been added by us. 

a In 1910 there were also reported 65,792,000 apple trees not of bearing age. No account was 
taken of such trees in the earlier censuses. 



Table II. — The Value of Specified Kinds of Fruits Produced in the 
United States in 1899 and in 1909. 

.As reported in the Twelfth and Thirteenth Census.) (Prom Table 36.) 



Total. 



Orchard 

Products . 1 



Grapes. 2 . 



Small 
Fruits. 



Sub-tropical 
Fruits. 3 



1899, _ ] $131,098,790 

1909, - 217,575,542 



$83, 750,961 
140,867,347 



$14,090,234 

22,026,961 



$25,029,757 
29,974,481 



$8,227,8' ; :S 
24,706,753 



1 . Including value of cider, vinegar, &c, in 1899, but not in 1909. 

2 . Including value of raisins, wine, &c, in 1899, but not in 1909. The number of vines and 
production of grapes was as follows: 

1899, No. of vines, 182,227,655; fruit, 1,300,751,066 lbs; wine, 31.671,111 gal. 
1909, No. of vines, 224,097,719; fruit, 2,570,936,310 lbs.; value. $22,025,060. 

3 . Includes bananas, citrons, figs, guava, kaki, lemons, olives, oranges, limes, pineapples, 
pomelos, and unclassified subtropical fruits. 

This relative position of the apple is doubtless to be attributed 
to its greater certainty of a crop, the many uses and long season of 
the fruit, and its wholesome effect upon health in general. 

In spite of the present magnitude of the industry, however, the 
present movement into it is apparently more rapid than ever before. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 403 

Orchards of thousands of acres, under experl direction, are being 
projected and established. Leading fruit regions reporl more trees 
recently planted than are now in bearing. The demand for apple 
trees is so great thai the wholesale price has practically doubled 
in the last two years, and in spite of tins gome of our largest nurseries 
are sold out completely by February or earlier. In short, a regular 
apple boom seems to be in possession of the favored regions through- 
out the country : and, with the increasing demands for all food pro- 
ducts, with the high returns available under proper conditions, and 
with the opportunity afforded for an open-air life, no general check 
in the growth of the industry is now in sight. 

In view of all this, it has been suggested that the danger of over- 
production is impending. But judging from past experience, this 
danger is probably relatively slight, with the possible exceptions 
of occasional years and of fruit in the lower grades. In fact, the 
failure of production to keep pace with The demands and with the 
increase in planting is one of the marked features at the present 
time. Thus in Table I, between 1890 and 1900, it will be noted that 
the increase in number of bearing apple trees is 67.3 per cent., while 
the increase in yield is only 22.5 per cent. During that period, there- 
fore, the increase in decs w;is about three times as rapid as that 
iu yield. 

This same general fact is brought out more forcibly in the estimates 
of one of our leading agricultural papers. Its estimates of the apple 
crops for the past eleven years are shown in Table III. As compared 
with the census figures, these estimates are noticeably lower, and 
their accuracy is of course unknown to the writer. They are said 
to be prepared with considerable care, however, upon the estimates of 
many observers in the various regions covered, and they are at least 
interesting in their exhibit of the trend of production for the years 
indicated. 



404 



ANNUAL REPORT OP 



Off. Doc 









; o -* co ■* 



£8838 

h O « l» H 

ffl 



S 5b rH ^ m 
cb ,_; 



S5III 









rC| O 



•OH-] 



■3k 



g ^ ® ' 

a fc £ 

© <y <D 
OKr? 



88 









iSSS 



l-ttH«rH 



8S88 

rH r-t Oi rH 



^ CO o 



00 O ' -H _^ 



§§ 



d.5 



o £ 



a"/ aa &m~ es 



a a 

p -gSosg&Sj 
O • * O o S H^pe-" 



H 

gssssagr. 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



4 or, 



to 












i;«SSnHnwnSMi<'»H'*6ic'iSSN6iinwHHn 1 -. 8ei-nHHS 

CO (H >H 1-4 HH« 

m 

giiiis'isiisgli'sg^^ 

EcS^S^ScSS^SOr-lOCNi-ltOaOiOCOCOlOCO-ri-lr-l iH iH 9! ® •* «B ©4C3 i-<c5 

a 
|sSg8Sg8g888"8"S8"S8^^8^S8"8SSS^ig8S88'g8 

« ■* (N rHrH l-T ■-< ' iH CO 

n 



588885 



38S8S883888S88888S98888S88S&S88888 



!SS: 



!8S88S88c28gS8888S88S88S8c|g 



lO CO CS> CO r-i C>* <N 






iililllillilillll: 



£ CO L 
^ ?£> Irt ct 



- w :';?■' c 



94c>OQeooeio$oocccccoc>ooeoeeg 

-. : . i* 2 ■-. '- c I - :i => Z SOio^OftCJSSaoOOOQi 

t r: t- rn h o co h io »o * n ci « it. w m c *r « r. o^ io t- cq < 



CO CM i-l 



rl i-i r-< CM 



i a 

■ a 

aTMo 
° > 3 






.>>a 

a; es 

w > 4) 



w ai oj 



j"C a 
! o a fe 

:■= p a> 



S3 S - 



o2^,5p;2u;?: 



II 



rfaaa 



oS5SOo£££ 



x 



'So • - .. - - S 
S S 3 a a - 



406 ANNUAL REPORT OF Off. Doc. 

Need of Better Knowledge. 

Part of the failure to increase in production, indicated in Table III, 
is doubtless due to lack of knowledge on the part of those immediately 
engaged in the industry. Undoubtedly great loss and waste could 
now be avoided, if only the best of our present knowledge were con- 
stantly applied. 

But another part of the failure must be attributed to the need 
of more and better knowledge on the part even of official horticul- 
turists. We need to know more concerning the exact crop require- 
ments of the apple; more of just what constitutes optimum conditions 
throughout the life of the tree and throughout the entire range of 
operations from choice of soil to market disposal. We should know 
more exactly which factors tend to promote and which to hinder such 
conditions; exactly why and how one practice is beneficial while 
another is not; and just what the characteristic effects of the various 
influences are, so that conditions in any given case may be properly 
diagnosed. Such things incidentally require a more intimate knowl- 
edge of the exact composition of the crop and its different parts, and 
especially more light on the characteristic functions and effects of 
the various mineral elements concerned. The annual draft upon 
minerals should also be known, since they are neither capable of 
being created nor of indefinite withdrawal from the soil. 

It is quite evident that the goal outlined above will not be reached 
in a day. Our problem is especially difficult in the case of the apple 
because of its perennial and long-time nature. This is no sufficient 
reason for not facing it directly, making all possible studies and 
tests immediately upon the apple itself, and supplementing these 
with the relevant facts and principles that are being established for 
plants in general. In fact, the importance of the industry demands 
that this be done. 

The effects of such a study, however, will not be confined merely 
to the apple industry, nor even to horticultural instruction relating 
to apples. They should tend strongly to develop a far more stable 
and scientific horticulture in general than that we now have. Much 
progress has been made, but much more remains to be made. Em- 
piricism, contentment with loose, isolated rules or with statements 
derived from very limited observation, reliance upon current or 
local practice rather than upon sound experimentation and the deter- 
mination of the best possible practice, — all these relics of earlier 
days should be eliminated. And if the studies outlined should have 
no other effect than to aid in accomplishing this thej^ would still be 
eminently worthy. 

Necessity for a Broad View. 

It will be noted that the subject covered by the present paper is 
rather broad, — too broad for a complete treatment in a single dis- 
cussion. We believe, however, that such a view is desirable, in the 
present stages at least for two reasons. First, because the various 
factors in orcharding are so inter-related that the conditions best 
for securing one desired effect arc often injurious in sonm other 
direction. Thus the conditions most favorable for yield are often 
less favorable for color or size, and vice versa. In such a case, the 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 407 

chief problem is to secure a proper balancing of the various factors 
concerned, — a problem which might readily be overlooked if either 
yield or color alone were the sole object of investigation. 

Second, a comprehensive view is desirable, as will be seen later, 
because orchard operations are likely to be without their proper 
effect unless conducted upon the limiting factor. In any given case, 
therefore, the determination of the limiter is one of the first things 
to be done. This requires a broad study, — one that involves all 
possible influential factors; and many of the wasted efforts in past 
experimentation have resulted from failure to recognize or properly 
provide for this fact. 

THE PRESENT PROBLEM VXD ITS FACTORS. 

In our present paper, the specific problem before us is a study of 
the causes or factors influencing certain phases of apple production. 
We wish to know how the yield, color, average size, and growth of 
apples may be affected. What are the characteristic effects of the 
various factors concerned, which factors tend to promote, which to 
hinder, and which are inactive or neutral regarding the proper de- 
velopment of apples in these respects. 1'pon these and their related 
questions, some of which have been indicated above, we have been 
working during the past four years, and the chief results are recorded 
here. 

In most cases in the present treatment, we have separated the 
possible factors into their two general (lasses, — environmental and 
internal. Both of these classes of influences must always be con- 
sidered in attempting to understand any observed difference in an 
orchard. 

Among the environmental factors, we have included the usual re- 
quirements of autotrophic plants, viz., moisture, light, plant food, 
temperature, carbon dioxid, and oxygen. Certain minimum amounts 
of each of these are required in order that any growth may occur. 
In the case of the apple, however, external conditions are further 
complicated by the influence of soils, climate, cultural methods, prun- 
ing, intercrops or (-overcrops, altitude and latitude, and certain living 
agents, such as fungi, bacteria, insects, and rodents. Also the rather 
uncertain intluence of stock upon cion, pollination influences, and 
even the planting distance or amount of crowding, — all are involved 
under environmental factors, and each may have its effect. 

The internal factors are less definable. Their existence is appar- 
ent, however, in the fad of varieties, and often in the otherwise 
unaccountable appearance of markedly ditl'erenl individuals or muta- 
tions within a variety, a number of instances of which are cited 
in the following pages. They can be distinguished with certainty 
only by eliminating all other possible causes and by determining 
whether or not the variations are inherited. Such variations, — due 
to internal causes, — are doubtless much more common than is ordi- 
narily supposed, despite the fact thai ninny apparent mutations have 
proved upon test not to be inherited. Whenever favorable mutations 
can be located, however, their importance is very great. In such 
cases the force of heredity produces effects, without any expenditure 
upon our part, that might otherwise be attainable only with great 
difficulty of not at all. 



408 ANNUAL REPORT OF Off. Doc 

The "Optimum" Principle. 

In dealing with so many factors, it is essential to have a working 
hypothesis. Some unifying principle is needed to guide one's action 
and to assist in understanding things otherwise hazy. Such a prin- 
ciple or hypothesis has been worked out in connection with other 
plants. It may be illustrated by the studies upon the big bamboo 
in Japan and Ceylon. When, this plant was studied by Shibata in 
Japan, it was found that growth varies with temperature. But 
when studied by Lock in Ceylon, it appeared that growth follows 
the moisture supply. Bringing these two facts together, it became 
evident that growth in the bamboo follows variations in the factor 
that was present in least amount relative to requirements. 1 This 
principle apparently holds roughly for growth and development 
in all plants. The so-called "law of the minimum" is a partial ex- 
pression of it, and a fuller expression is developed below. 

In general, it holds that in order to grow at all, plants require 
certain minimum amounts of certain factors. With progressive in- 
crease in the amounts of these necessary factors, growth — or some 
other physiological result — increases up to a more or less definite 
point, called the optimum. With further increase in the factors, 
growth again diminishes, until at another more or less definite point 
called the maximum, the amount or intensity becomes so great that 
all growth is stopped. These changes may as a rule be represented 
by a curve exhibiting minimum, optimum, and maximum points. 
Such a curve ''may be constructed not only for the ash constituents, 
but also for the organic food, for the action of light, and indeed for 
all factors or agencies which produce a perceptible effect only at 
a certain degree of concentration, above which their action gradually 
increases until the optimal effect is produced." 2 

A fair statement of the principle, therefore, is that plant growth 
increases as all factors approach the optimum. Thus, a decrease 
from the maximum evidently may promote growth just as effectively 
as an increase from a minimum. We suggest, therefore, that the 
"law of the optimum" is much closer to the facts and a better name 
for the principle unsolved than the so-called "law of the minimum," 
which has been attributed to Liebig. 

The experimental and practical importance of this appears in the 
fact that the one factor farthest from its optimum, either below or 
above, may essentially control the results from a crop. In the past, 
the factors below their optimums have received most of the atten- 
tion, though excesses in some other factors may have been the limiters 
at times when the lower factors were being varied. The excesses 
are more frequent than is generally supposed. Thus in Arizona, 
excessive light is frequently the chief erop-limiter. In Colorado, 
according to Head den, 3 certain areas are barren because of too much 
nitrogen. Excessive moisture may be the limiter, as is usually the 
case in our poorly drained lands. In some orchards, moreover, in the 
writer's judment, the limiter has been excessive pruning. 

From all viewpoints, therefore, a complete statement of what we 
may call the "optimum principle," or the optimum hypothesis, is that 

x See article by F. F. Blackmail on "Optima and Limiting Factors," Annals of Botany, April, 
1905. pp. 281 to 295. 
2 Pietfer. Physiology of Plants, I. 413-414. 
3 Headden. Colorado Bui. 155, 1910. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 40a 

plant growth and development increase as the most distant essential 
factors approach the optimum. This is essentially the principle upon 
which most of our orchard experiments have been organized. 

Some Experimental Rules and Precautions. 

This is a phase of our subject into which the writer hesitates to 
enter, partly because in so doing we may be "carrying coals to New- 
castle." It is such a comomn experience, however, in looking over- 
results of experiments, to find satisfactory conclusions impossible 
on account of defects in the original plan, that we have decided to 
call attention here to some of the more important rules and pre- 
cautions which in our judgment should be considered in the estab- 
lishment of a satisfactory set of orchard experiments. Some of these 
points have been particularly impressed upon us since the beginning 
of our experiments. In most cases, however, they were considered, 
and incorporated in our experiments. At the risk, therefore, of 
offering some unnecessary advice, we make the following suggestions: 

(1). The experiments should be sufficiently checked. 

What constitutes sufficient checking varies with the kind of experi- 
ment. In fertilizer tests, checks are especially necessary. All such 
experiments should not fail to have a. check at each end of the series 
and others distributed among the treated plots at least one every 
fourth or fifth plot. If the soil or other conditions are noticeably 
variable, it will be best to make every third plot a check. Fewer 
untreated plots than this only lead to doubt in the end, and make it 
impossible to say just what factors were operative in bringing about 
the observed differences. In spraying experiments containing several 
treatments, usually fewer checks are available without unduly ex- 
posing some of the treatments to unsprayed conditions. At least 
a check at each end should be provided, however, and ordinarily this 
is enough. In some other types of experiments, such as comparisons 
of cultural methods, the various treatments may be so arranged that 
no regular checks are required. 

(2). Only one factor should be purposely varied at a time. 

In other words, the questions considered should be kept clear and 
distinct, with no overlapping, and with all other factors kept as 
uniform as possible. For example, if one is trying to determine the 
influence of plant food upon yield, all questions of time of applica- 
tion, different amounts, or of varying proportions of ingredients 
should be rigidly excluded, so far as experimental variations are 
concerned; or else they should be relegated to distinct portions of the 
experiment. 

(8). In general, the early work should be a qualitative study of 
factors rather than quantitative. 

This simply means that we should first try to isolate the limiters, 
or determine which are the influential factors, before attempting 
to measure the exact influence of any one. On account of the frequent 
reversals in our preconceived opinions, it needs to be comprehensive 
enough to give all possible limiters a chance to operate. After the 



410 ANNUAL REPORT OF Off. Doc 

limiters are isolated, the quantitative study may begin, with the 
idea of bringing out especially the optimum conditions of the fac- 
tors found important. Failure to distinguish clearly between these 
qualitative and quantitative phases, or the attempt to study the 
latter before the former, are important causes of failure and wasted 
efforts in many experiments. 

For making a really thorough quantitative study, probably the best 
general plan is the ''triangle method" of fertilizer application pro- 
posed by Schreiner. 1 It would have to be modified considerably, how- 
ever, to make it practicable for orchard trees. 

(4). The differences in treatment should be distinct. 

By this we mean that the experimenfal variations should be large 
enough to practically guarantee evident differences in results, if the 
factors being tested have any influence. In other words, the investi 
gative net should not be too fine-meshed, at least not until some of 
the larger points have been definitely established. This fault has 
appeared in some of the more recent experiments that have come 
to our attention. 

(5). The plots should be large enough to eliminate individuality 
of the trees, and to provide, at least partially, against loss during 
the progress of the experiment. 

Just how many trees will be required for this evidently can not 
be stated. But at least 10 trees per plot should be provided, and 
more are preferable, especially if more than one variety is involved. 

(6). Special provision should be made to prevent the tree roots 
of one plot from foraging upon the other plots. 

This is a fruitful source of confused data. The provision is probably 
best accomplished by having an unconsidered row between all plots, 
and if there is much danger of surface washing it is the only safe 
way. If the experiment is already large, however, this method is 
often impracticable. In such cases probably the best thing to do is 
to arrange the trees in two or more rows per plot, locate the plots 
with reference to slope so as to largely or wholly avoid cross-leaching, 
and then keep the feeding roots within bounds by deep plowing and 
subsoil ihg in the middle of the interspaces between the plots. 

(7). For greater convenience and uniformity, the number of trees 
in all plots should be the same, throughout any given experiment. 

This avoids some of the computations required when the plots are 
irregular, and thus reduces the chances for error, besides keeping 
closer to the actual field results. 

(8). Sufficient time should be allowed, before definite conclusions 
are attempted. 

At present, the writer is unable to say just what amount of time is 
sufficient, in connection with apples. Certain things, such as the 
usual biennial bearing habit and the formation of fruit buds during 

'This method has been devised by Oswald Schreiner of the United States Bureau of Soils, 
especially for use in general farm crops. (See Bureau of Soils Bui. 70: 16-19, 1910). 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 41 i 

the preceding season, make relatively long periods necessary. Ten 
years have been alloted for our present experiments, which are now 
in i he fifth year. 

An approximate test for the sufficient duration of an experiment 
may he when effects of the treatment have heconie fairly constant. 
This however is yet to he demonstrated, and at least two or three 
years additional after the effect has become apparently constant, or 
a number of duplicate tests, will usually he required to determine 
the actual constancy of an effect. 

Other important requisites will readily occur to the reader, such 
as sufficient duplication, thorough and permanent charting and label- 
ing of trees, avoidance of incompatibles in the fertilizer mixtures, 1 
adaptation of treatments to the particular demands of the crop, ad- 
justment of treatments so as to throw light upon current practice, 
and especially the avoidance of any material change in plan after 
the experiment is once well started. 

With the observance of these precautions in laying out field experi- 
ments, we believe that more satisfactory progress will be made, with 
less disappointment to all concerned. 

GENERAL TYPES AND EXTENT OF THE PENNSYLVANIA ORCHARD 

EXPERIMENTS. 

The original data herein recorded are obtained, as stated above, 
from experiments started by the writer, in the spring of 1907 and 
1908, acting for the Pennsylvania Experiment Station. Most of the 
data arc 1 taken from the older experiments, Numbers 215 to 221. 
A general description of these experiments in their early stages was 
given in the Pennsylvania Annual Report for 1907-8, pages 192-198. 
Additional notes and results for the first three years have appeared 
in our Annual Reports from 1908 to 1910 and in Bulletins 91 and 
100. The latter account summarizes (he important results obtained 
up to the close of the third year. Such portions of these publications 
as seemed necessary to an understanding of the work as a wdiole are 
repeated here, though in case of doubt the reader is referred to the 
earlier bulletins and reports. 

In the present report, data for four years are given; the plan of 
presenting it is somewhat extended, other experiments and other 
phases of these same experiments are considered, and results ob- 
tained elsewhere are brought into the discussion with much greater 
fullness than has been done heretofore; also the approximate composi- 
tion of the fruit and vegetative parts of the apple, and the annual 
draft per tree and per acre have been worked out, and they are pre- 
sented herewith, together with our present knowledge of the char- 
acteristic functions of some of the more important minerals found 
in plants. 

The types of our experiments upon apples that are now in opera-, 
tion are as follows: ill The influence of plant food as affected by 
fertilizers; (2) the influence of different methods of soil management, 
with ami without manures: (3) the influence of various cover crops 
and intercrops upon free-growth and f ruitf ulness ; (4) the influence 
of cion-selection from superior individuals: (5) the influence of dif- 
ferent stocks: and (0) the influence of varieties. Besides these larger 
and more direct experiments, we have others: (7) on the cause of 
injuries following certain fertilizer applications; (8) value of certain 

iSoe Experiment Station Work, III, No. 16, p. 421, 1910. 



412 



ANNUAL REPORT OF 



Off. Doc. 



applications in borer-control; and (9) a continuation of our past 
work upon spray materials and their use. It is with the first four 
types that we are especially concerned in this report, although some 
reference is made to most of the others. 

Including the work at State College, we now have in operation 
a total of eighteen experiments, in twelve orchards, located in various 
parts of the state. These experiments involve ten soil types, 3,660 
trees, and cover 91 acres. Forty-nine acres, including 2,219 trees of 
twelve varieties, are in partial or full bearing. 

Since the experiments were started, they have produced 829,527 
pounds of fruit. This fruit has been studied from three view-points. 
Besides the work with the fruit, studies have been made upon wood 
growth, root-distribution in the different soils and varieties, and 
upon leaf-weights as an index to the effect of fertilizer applications. 
The use of leaf weights was given up after the third year, after 
collecting, drying and weighing many thousands of leaves from the 
various treatments. This was because of the fact that the average 
leaf weights showed no definite correlation with fertilizer applica- 
tions, though their color, relative abundance, and persistence on the 
trees, as well as other characters, showed marked correlation. 

The exact locations, soil types and varieties involved in the experi- 
ments away from the College are shown in Table IV. 



TABLE 



IV.— LOCATION AND OTHER DATA ON 
MENTS AWAY FROM THE COLIEGE. 



EXPERT- 



Ex. 
No. 




Owner of 
Orchard. 


Soil. 


Varieties. 


Age. 
1910. 


Number 
of Trees. 


815 


Adams. -- .__ 


Tyson Brothers, 


Po r t c r's (?) 
loam. 


York Imperial and 
Stayman Winseap. 


Yr. 

11 


160 


21C 


Franklin. 


D. M. Wertz,— 


Mont alto flne x 
sandy loam. 


York Imperial and 
Jonathan. 


11 


160 


220 


Bedford. 


Mrs. S.B. Brown, 


DeKalb stony 
loam. 


York Imperial and 
Baldwin. 


12 &22 


160 


217 


Franklin, ... 


J. H. Ledy, — 


Montalto loam 1 , 


York Imperial and 
Gano. 


17 


358 


218 
219 


Franklin, ... 


J. A. Nieodemus. 


Hagerstown clay 
loam 1 . 


York Imperial and 
Albemarle. 


11 &15 


400 


Bedford 


J. R. Sleek. 


F r a n k s t own 
stony loam. 


Y. Imperial, Jona- 
than, Ben Davis 
and Gano. 


8 


320 


221 


Wyoming, — 


F. H. Fassett,— 


Chenango fi n e 
sandy loam. 1 


Northern Spy and 
Baldwin. 


38 


115 


336 


Chester, 


A. D. Strode, — 


Chester loam,— 


Grimes, Smokehouse 
& Stayman Wine- 
sap. 


8-10 


120&105 2 


337 s 


Mercer, 


St. Paul's Or- 
phans' Home. 


Volusia silt 
loam. 1 


Northern Spy, Bald- 
win & Rome. 


3 


ISO & ISO 


388 


Lawrence, ._ 


J. B. Johnston,- 


Volusia silt 
loam. 1 




22 


80 & 105 






S39 


Bradford, ._ 


F. T. Mynard,. 


Lackawanna silt 
loam. 


Baldwin and Falla 
water. 


16 


120 & 16 



1 Soils not mapped as yet but probably closest to the types indicated according to the 
observations of C F. Shaw and H. J. Wilder. All these soils are described and discussed 
below, immediately after the descriptions of experimental plans. 

2 In the two sets of figures in this and the following experiments, the first gives the 
number of trees under fertilizer treatment, the second those under different cultural methods. 
In experiment 339, the later includes only the sod mulch plot. 

«. Trees set out in connection with these experiments, henct not yet in bearing. 



No. 20. THE PENNSYLVANIA STATE .COLLEGE. 413 

The first three experiments, 215, 21G and 220, comprise what may 
be called our straight fertilizer experiments. Each contains 16 plots 
of 10 trees each, making a total of 480 trees. The next four are 
experiments upon cultural methods, with and without manures. 
They contain from 14 to 50 trees per plot and make a total of 1,193 
trees. The last four experiments are a combination of fertilizers and 
cultural methods. They contain from 8 to 45, trees per plot and 
make a total of 90G trees. 

J'hui of Fertiliser Experiments. 
The general plan of our fertilizer experiments is given in Figure 1. 



I. Check. (No 


treatment.) 








II. 


Nitrogen and phosphate 








III. 


Nitrogen t 


nd potash. 








IV. 


Check. 










V. 


Phosphate 


md potash 


in 


muriate 


form.) 


VI. 


Phosphate 


and potash 


in 


sulphate 


form.) 


VII. 


Check. 










1 VIII 


. Nitrogen, 


phosphate 


aid 


pota»h. 




IX. 

1 . 


Nitrogen. 










X. 


Check. 










XI. 


Phosphate 


(in form of 


acid phosphate.) 


XII. 


Phosphate 


(In form 


of 


"floats. 


') 


XIII 


. Check. 










XIV 


Stable manure. 








XV. 


Lime. 










XVI 


Check. 











Figure 1. Plan of experiment on influence of fertilizers. 

In this experiment, each plot contains 10 trees, usually of two 
varieties. 

The nitrogen, phosphates and potash are applied at the rates of 
50 lb. of N, 100 lb. of P 2 C%, and 150 lb. K 2 per acre, in all cases. 
The nitrogen is applied in the form of nitrate of soda and dried 
blood, in such amounts as to carry about equal quantities of N in 
each. This is primarily to prolong the effect over more of the season, 
and perhaps reduce danger of leaching, since the N in dried blood 
is less readily available than in nitrate of soda. As indicated in 
Figure I, plots V and VI compare the muriate and sulfate as carriers 
of potash, and XI and XII compare acid phosphate and "floats" 
as carriers of phosphorus. The manure is applied at the rate of 
12 tons per acre and the lime at 1000 pounds per acre. All applica- 
tions are made annually. Four of these experiments are in opera- 
tion, one of them being on young trees located at the College. The 
locations, numbers of trees, kinds of soil, etc., in the other three 
fertilizer experiments, are given above. 



414 



ANNUAL REPORT OP 



Off. Doc 



Plan of the Experiments on Cultural Methods and Manures. 

The general plan of our experiments on cultural methods and 
manures is given in Figure 2. 



I. 

Clean Tillage. 
40 trees. 


IV. 

Tillage and cover 

crop. 

40 trees. 


VII. 
Sod-mulch, 

40 trees. 


X. 

Sod. 
40 trees. 


II. 

Tillage and Manure. 
20 trees. 


V. 

Tillage, cover-crop 

and manure. 

20 trees. 


VIII. XI. 
Sod-mulch and Sod and manure, 
manure. 20 trees. 
20 trees. 


III. 
Tillage and commer- 
cial fertilizer. 
20 trees. 


VI. 

Tillage, cover-crop 

and commercial 

fertilizer. 

20 trees. 


IX. 

Sod-mulch and 

commercial fertilizer. 

20 trees. 


XII. 

Sod and commercial 
fertilizer. 
20 trees. 



Figure 2. Plan of experiments on cultural methods and manures. 

In most cases, since so many trees are required, we have been 
compelled to modify this plan somewhat, both in numbers of trees 
and in arrangement of plots, in order to make it fit the conditions 
available. The essentials, however, have not been disturbed. As 
indicated in our discussion of experimental rules above, the plan of 
this experiment might be improved by making the number of trees 
uniform in all plots throughout the experiment, though the deviation 
here is not serious. 

The locations, soils, numbers of trees, etc., are to be found in 
Table IV and its following discussion. As shown in the figure, this 
experiment tests four methods of soil management, viz., clean tillage 
and covercrop, sod-mulch, and sod. Each treatment occurs both 
without fertilization and with it in two forms. The stable manure 
is applied annually at the rate of 12 tons per acre. The commercial 
fertilizer is a so-called "complete" one and is applied at the rate 
of 30 pounds N, 60 pounds P..O-, and 100 pounds ICO per acre. More 
actual plant food is thus being applied in the manure, since 12 tons 
of average stable manure are estimated to contain about 120 pounds 
each of N and K 2 0, and about SO pounds of P 2 5 . At present retail 
prices, the fertilizer application costs $12.35 per acre. 1 

On the mulch plot, all herbage remains in the orchard, the first 
cutting being raked to the trees, as a mulch, and an additional mulch 
of old straw, swamp hay or buckwheat straw at the rate of about 3 
tons per acre is applied annually. In this latter respect, it differs 
from the so-called "Hitchings plan," and, as a conserver of moisture, 
it is undoubtedly very much better. On the sod plot, the first cutting 
of herbage is removed from the orchard and the second is left where 
it falls. The tillage plots are all cultivated from May until about the 

1 A 30-50-50 application per acre, costing about $9.75, would probably give equal results; and 
even this cost could be reduced to about $4.50 per acre by getting the nitrogen through green 
manuring crops. The real economy of the latter operation will depend upon cost of labor, 
seed, ease of getting a stand, &c. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 4J5 

middle of -July, when those receiving the cover crops are seeded to 
crimson clover, hairy vetch, or medium red clover and alfiike, either 
singly or in combination. An effort has also been made to keep 
some leguminous plants in the permanent cover used in experiments 
VII to XII, though no1 with as much success as desired. 

Plan of the "Combination'' Experiments. 

These experiments are a combination of certain portions of the 
two types just described. They are rather more general in their 
scope, and they aim at two factors instead of one. The general plan 
is shown in Figure 3. 



I. Check. (No treatment) 10 to 15 trees. 



II. 


Niitrogen 


m< l phosphat 


>. (No. 


of trees 


uniform 


in plots 


I to X.) 


III. 


Nitrogen 


and potash. 












IV. 


Cheek. 














V. 


Phosphate 


and potash. 












VI. 


Nitrogen, 


phosphate 


and potash. 








VII 


Check. 














VIII. Stable 


manure. 












IX. 


Lime. 














X. 


Check. 














XI. 


Tillage and covererop. 


30 to 


40 trees 








XII 


Sod-mulch. 30 to 40 


trees. 











XIII. Sod. 30 to 40 trees. 



Figure 3. Plan of "Combination" Experiments on Fertilizers and 

Cultural Methods. 

The applications in this group of experiments are the same as 
in the fertilizer experiments described above. The treatments of 
plots XI to XIII are the same as described for the similar plots in 
the cultural method experiments. Some slight modifications in this 
general plan were also found necessary in the installations in or- 
chards already set. In experiment 337, which was set out in con- 
nection with these experiments, an additional plot was included. 
Its purpose is to test the effect of intercrops upon the trees during 
the early years. The locations, soils, varieties, etc., are stated in 
Table IV, and in the following discussion. 

Description of Soils Involved. 

In Table IV, the technical names of the soils involved in our 
experiments are given. In the present section, these soils are de- 
scribed, their approximate extent and location are indicated, and 
the chief facts in the previous treatment of the various experimental 
areas are given. The naming of the soils, and their technical descrip- 
tions and approximate extents, have been secured with the aid of 
H. J. Wilder of the U. 8. Bureau of Roils, and C. F. Shaw, who is 
20 



410 ANNUAL REPORT OF Off. Doc 

also connected with the Bureau and is in charge of the soils work 
in The Pennsylvania State College. The soils are referred to in 
connection with their experiment numbers. 

Expt. 215. The soil in this experiment has been mapped as Porter's 
loam, which it resembles, but both Wilder and Shaw agree that it 
is a different series from the Porter soils. The former has proposed 
that the name of that series be changed to Floradale, and is using 
this name in his report on fruit soils. This name, however, has not 
been approved as yet. The largest areas of it are found in Adams 
County although some small patches occur in York County. It is 
generally considered a good fruit soil. 

The surface soil consists of a heavy loam or clay loam, brown or 
dark gray in color, from G to 15 inches deep. The subsoil consists 
of pale red or light brown clay loam or clay. From. 15 to 25 per 
cent, of stones and angular rock fragments are usually present in both 
soil and sub soil but they are never of sufficient size to materially 
impede cultivation. 

The previous treatment received by the trees in this experiment was 
as follows : An intercropping system, consisting of potatoes one year 
followed by timothy and clover two years, had been the practice. A 
gradually widening strip about the trees was given annual cultiva- 
tion. The hay was plowed under in the fall and the space between 
the tilled strips Avas planted to potatoes in the spring, with the 
addition of about 1,000 pounds per acre of a 0-12-10 fertilizer in 
the potato rows. The orchard was in the second year of the hay 
crop when our experiment started. 

Expt. 216. The soil of this experiment is much like the more widely 
distributed DeKalb soils, but is sufficiently different to be classed 
separately under the title of Montalto fine sandy loam. This series 
occurs along the north slope of South Mountain and is found best 
developed in Franklin and Berks Counties. The soils occur as slopes 
on the lower flank and foot of the mountain and are derived from 
iron stones, quartzites, cherts and other rocks. They are locally 
known as ironstone lands. One of the characteristics of this soil 
is the tendency to become sticky when wet which makes it hard to 
plow. 

The soil had been cropped in general farm crops for many years, 
with moderate success before being set to fruit. The filler system 
with peaches is the treatment that had been in use in the orchard, 
and during the later years moderate annual dressings of bone and 
sulphate of potash had been applied to the peach trees. It is gen- 
erally considered to be a very good fruit soil, especially for peaches, 
some striking successes having been made upon similar locations in 
this valley. 

The surface consists of 6 to 8 inches of a yellowish brown or reddish 
yellow, gritty or sandy loam resting on a loose reddish yellow loam 
subsoil, which grades into a someAvhat sticky loam or clay at the 
depth of 24 to 36 inches. Soil and subsoil contain 30 to GO per cent, 
of fine angular chert fragments. 

Expt. 220. As stated in Table IV, this soil is DeKalb stony loam. 
Considerable areas are found in Lancaster, Lebanon and Mont- 
omery Counties in Pennsylvania. 

The surface soil consists of brown, yellow, or gray, medium sandy 
loam from 6 to 10 inches deep. The subsoil ranges from heavy yellow 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 417 

sandy loam to light red clay loam, resting upon a mass of sandstone 
and quartzite fragments. Both soil and subsoil contain a large 
quantity of sandstone, conglomerate and sandy calcareous shale 
fragments. 

Locally, the soil of this experiment would be described as a shallow, 
very stony, foothill soil, immediately underlaid by such masses of 
sandstone and quartzite as to have the effect of solid rock. It had 
been cropped for many years, until it is said to have become so poor 
that it would not produce five bushels of com to the acre, nor return 
the seed sown for oats. Despite this, the Yorks have produced 
profitable crops, and supported the family. When our experiment 
started, however, both fruit and twig growth were small. It appeared 
to be a soil that had been cropped into almost complete unproductive- 
ness, first as a producer of field crops and then as a producer of fruit ; 
hence it seemed a favorable situation in which to test the influence 
of fertilizers on apples. 

Expt. 217. The soil in this experiment has been designated as 
Montalto loam. Its description and discussion are the same as that 
given above for 210 with the exception that, being a loam, it does 
not contain so much sand and grit. 

Expt. 218 As indicated in Table IV, the orchard of J. A. Nicode- 
mus is located upon a Hagerstown clay loam soil. This is a residual, 
limestone soil. The soil is a heavy, reddish, silty loam, averaging 
about 24 inches in depth, overlying stiff, tenacious, red clay. The 
type occupies rolling valley land and is derived from the weather- 
ing of pure, massive limestone. No fertilizer had been applied to 
the trees in so far as we were able to leam. 

This soil is practically the same as that found in our Experiment 
Station farm at State College. It is described by C. F. Shaw, in our 
Annual Report for 1907-8 pp. 09-70, as follows. "The surface soil 
of the Hagerstown clay loam consists of from 6 to 8 inches of rather 
light and silty clay loam of a yellow-brown to red-brown color. The 
subsoil consists of a medium to heavy red clay which grows heavier 
and stiller with depth. The soil section in most cases contains from 
5 per cent, to 15 per cent, of small angular chert and limestone frag- 
ments. It is easily cultivated and the drainage, both surface and 
underground, is good." 

Expt. 219. The soil in J. R. Sleek's orchard was called DeKalb 
shale loam in our Bulletin 100, but in the recent survey of the county 
it has been named Frankstown stony loam. The so-called Chestnut 
Ridge in Bedford County is one of the largest known areas, and 
smaller areas are found in Perry, Juniata and Mifflin Counties. 
There are probably not over 100 square miles in this series. The 
soil is locally reputed to be the best in Bedford County for the pro- 
duction of corn and rye. It is said never to "cake" and to be always 
friable, regardless of amount of moisture contained when tilled. 

The surface soil is a gray silt loam, to 8 inches deep, resting on 
a light gray sandy loam which grades into a yellow loam at 3G inches. 
The soil and subsoil contain 20 to 60 per cent, of flat gravel or 
angular rock fragments locally known as "bastard limestone." Where 
it occurs, this soil occupies one slope of a ridge, the top and opposite 
side of which is derived from the true limestones. In other cases, 
where underlying rocks do not stand at a sharp angle, the soils may 
occupy the whole of a rounded or eroded ridge. 
' i»7 -20— 1910 



418 ANNUAL REPORT OP Off. Doc 

E.rpt. 221 . The soil type found in this experiment, which hereto- 
fore has not had a series name, has been named Chenango by H. J. 
Wilder, and as such appears in his fruitsoils report. It has appar- 
ently been deposited in a temporary lake bed, formed by the partial 
stoppage of the Susquehanna River in cutting through the moun- 
tains. There is a considerable amount of such soils along the streams 
in this part of Pennsylvania. It is considered good fruit land. The 
surface soil is a sandy loam. The subsoil is a yellowish fine sandy 
loam for about two feet. This is underlaid with sand, becoming 
gravelly and continuing to a depth of about 30 feet. 

The previous treatment of this orchard was as follows. The trees 
were set in the spring of 1873. It was cultivated for the first 12 years 
and intercropped with potatoes, with the exception of corn two years 
and beans one year. It was then sowed down for two years, re- 
plowed in 1887, and sowed in oats one year. In 1888, it was in buck- 
wheat and was sowed to clover, in which it remained until 189S. 
During this time it was manured every other year at the rate of 
about 500 pounds per tree, one-half of the orchard being manured 
one year and the other half, the next. 

In 1898, the west half of the orchard was plowed and sowed in 
cowpeas. The effect on the trees was so favorable that since then 
the orchard has been plowed every other year, one-half being plowed 
each year and the other half remaining in crimson clover sown as 
a cover crop. The manuring continued as above. These operations 
continued until 1007. When first seen by the writer, the part of the 
orchard used for our experiment was in clover and red top. 

Expt. 336. This soil is predominatingly Chester loam although 
both loam and heavy silt loam of the Chester series are found in the 
orchard. This series occurs in the northern part of the Piedmont 
having been found and mapped only in Pennsylvania, Maryland and 
Virginia. In the IT. S. Bureau of Soil's Survey of Chester County, 
it is said to comprise about 41 per cent, of the county. It has been 
formed principally by the breaking down of gneisses, aided to a less 
extent by residues from mica schists. The mica often gives a decided 
sparkle to the soil of this vicinity and should indicate an abundant 
potash supply. 

In general, the surface soil in Chester loam consists of a mellow, 
brown or yellowish loam, sometimes slightly sandy, containing some 
mica. This is underlaid by a heavy yellow loam subsoil grading into 
clay loam, which in lower depths becomes somewhat lighter in texture 
and more micaceous. The color is sometimes reddish yellow or red. 

The soil is well adapted to general farming, corn, oats and wheat 
being raised successfully. Its adaptation for fruits appears good, 
judging from the large growth and early bearing of the trees in Mr. 
Strode's orchards; and also from the success of pears in the neigh- 
borhood, especially Seckels. The large nursery industry of the 
county is also being conducted almost entirely on this soil. 

Expt. 337-388. In the opinion of H. J. Wilder, the soils of these 
two experiments are probably Volusia silt loam, as named in Table 
IV. The Volusia soils are found in eastern Ohio, southern New York 
and northern Pennsylvania. 

The soil of the Volusia silt loam, to an average depth of 8 inches, 
is a gray to a brown silty loam. The subsoil, to a depth of about 



pp.^cjg(iatjr) £> jntrCopfrrol. 
tjcpt. S32.(i9a trj Ferbilizafc-iok' 



Eipl 4|ofe 
(»-tr) 
Fertilizer I raj 



^1/ 



H 
Cleap Tillage 
CJ17HI bcorir?g, 

t^ep sod 



I. C^cck 



HE. ^. K. 






I n.P 



E.Wolf River. 



E G?eck 



3T P K. 



/^alc^ atpd 
/\ar?aro, 



— pzr PK^o^. 



MC^eck 



IXl 
Corp. Fertilizer 



is: 
Tillage 

opd 
Cover crop 



M/1.PK, n 



1. 1ST. 5 



P> 



IE Tblrpoi^ 



EPai 



igo? 



Z C^arpptor? 



j^-Narsery 
Trees 



_ /Median? 
Red Clover 



a: /^ 



<4 



X.C^cck 



Tillage 
a9d 

Intercrop 



XtAcid P»?os. 



HE Raw PI70S. 



SI Check 



Tillage, Covcrcrop 



— XyjLinpc 

Tillage, Covcrcrop 

apd Con;, fertilizer XZI Check 



XowpCQS 

*Soy£co9s 



jOats apd 
Cap a do Po,os 



XET^apure 



Alsike and 
Crirp. Clover 



2E Ry< 



WMillet 



M Rape 



Hf>uckwJ7eot- 



X Alfalfa 



Expt. 334-. 

(72 tr.J 

Stocks apd 

lop-workipg, 

(For Grir^es, 

K.i*9g a7d 

Jbr^at^ar;) 






Cs . 


•4} 


-U 


v£L 


- <fl 




-** 1. 


»o 


*» 


(0 


-2-«* 


<0 


61 f> >. 
»0& 


4J 


1 


V 


£* T 



(4 u > 



£xpt. 333 
(izotr.) 

Covercrops 
09 growth 



Fiq.4. Exp'to. 19 R-ogress ij> tl?e Exptl Apple Orchard at 6tote College, Pa. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 419 

two feet, is a light, yellow, silly loam, and below two feet, it usually 
becomes mottled with gray or drab. A considerable quantity of 
finely divided shale fragments are found in both soil and subsoil. 
II is" called locally a friable clay soil, underlaid at a depth of about 
two feet by -bard-pan." It is usually in need of drainage, though 
this is not especially evident in experiment 33& 

Ewpt. 339. This soil resembles those of the Upshur scries in some 
respects ami was so named in our Bulletin LOO. This past summer, 
however, it was named Lackawanna silt loam by the men who made 
the soil survey of Bradford County. This series covers considerable 
areas of the upland portions of the northeastern part of this state. 
It is a glaciated soil. 

The surface soil is a decidedly silt loam of varying shades of red 
resting on a dark red silly clay subsoil derived from feeble glaciation 
of red sandstones and shales. The series, as a whole, has a rolling 
topography and good drainage. The surface and subsoil contain 
large amounts of Hat stones derived from the underlying rocks. 

Some previous fertilization had been given to a part of the frees 
in this orchard. It consisted of wood ashes, and later of a local "fruit 
fertilizer" reinforced with muriate of potash. Grass, with occasional 
crops of buckwheat in which the crop was harvested, was the previous 
practice in the orchard. 

Orchard Experiments Located at the College. 

The principal orchard experiments now in operation at The Penn- 
sylvania State College are indicated in Table V. A preliminary ex- 
periment on pruning has also been started, but is not listed because 
of more comprehensive work to be undertaken later. 

Table V.— ORCHARD EXPERIMENTS LOCATED AT THE PENN 
8YLVANIA STATE COLLEGE. 



Kxpt. 
No. 



Subject Under Experiment. Varieties involved. Number 

of Trees. 



Cultural methods - York Imperial, Btayman, 288 

Winesap. Baldwin. 

"32 Fertilizers, ._ York Imperial, Stayman, 192 

Winesap. Baldwin. 

333 Cover crops York Imperial, Btayman, 120 

Winesap, Baldwin. 

334 Apple stocks, __ Indicated below, .. - 78 

335 Varieties and cion-selection, indicated below, :»*> 

408 Fertilizer injury 21 

409 Prevention of borers,' ._. 1« 



The general plans and arrangement of these experiments are shown 
in Figure t. 

The trees in this orchard were set in the spring of 1908. They cover 
28 and two-thirds acres. Allowing for some that are counted twice, 
they number 1,0:52 trees. One-year old Northern Spy trees were used 
as the stock in the first two experiments, 331 and 'A'.V2 ; and two year 
old Spy for about 135 trees of experiments 334 and 335. The trees 
of two rows of the latter were considerably affected with hairy root, 



ir This experiment is also being conducted upon peaches, In which a total of 20 trees is 
involved. 



420 ANNUAL REPORT OF Off. Doc 

now known to be one phase of the crown gall disease. 2 They were 
obtained too late to get other trees, however, so we thus have incident- 
ally an opportunity for making observations on the field behavior of 
this interesting disease. 

The trees of experiments 331 and 332 were top-worked in the 
spring of 1909 with tbe varieties indicated in the table, using cions 
of a single tree to the row in most cases. For most rows, the cions 
used were selected from single superior trees, which is also the case 
throughout experiment 334. The selection phase of our work, there- 
fore, overlaps some of the other experiments, but it is done so as to 
be uniform for all treatments and thus not to confuse the results 
from either viewpoint. This accounts, however, for some of the trees 
being counted twice, as indicated above. 

The age of the trees and the duration of these experiments are too 
brief for any important results as yet. Such data as appear to be 
valuable, however, are given later in their appropriate connections. 
These cover especially the present progress in our work upon certain 
fertilizer injuries and upon cion-selection. 

General Plan of Present Paper. 

In the present treatment of our subject, some of the principal fac- 
tors are considered twice, first from the viewpoint of the factors; 
and second, from that of the effects. In other words, each factor, 
on which we have data, is first considered in connection with its 
various effects; and then some of the effects, such as size or color, 
are considered, each in connection with the various factors that 
may be expected to affect it. As will be observed, most of the data 
on these points are original. Also much of that from the experiments 
or reports of others has been re-assembled or re-calculated, often from 
somewhat different viewpoints. 

The direct results of our experiments up to the time of the present 
report are given in pages 455 to 504. The results on any particular 
phase can be found most readily by consulting the summary and eon- 
tents given on pages 500 to 512. 

2 See Bulletin 213, U. S. Bureau of Plant Industry, 1911. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 421 

PLANT POOD AS A FACTOR IN APPLE PRODUCTION. 

Among fruit-growers and horticulturists generally, there is much 
difference of opinion as to the value and necessity of plant-food ap- 
plications to apple trees. The common reasons advanced against 
their use are: The deep-rooting habits of the trees; the high water- 
content of the fruit; the long growth season; the long preparation 
stage before fruiting; and the so-called off years for recuperation. 
But inasmuch as the off year may frequently be largely overcome 
by proper fertilization and other care, its existence would seem to 
lie more valuable as evidence in favor of fertilization than as a basis 
for argument against it. The same is true of the long preparatory 
stage before fruiting. This long growth period, without chance for 
rotation, during which considerable quantities of plant food are being 
locked up in the wood and blown away in the leaves, is likely to be 
more of a cause for fertilization than for the lack of it. Moreover, 
it is desirable that this long preliminary stage be shortened, and 
under optimum conditions this is accomplished. 

The supposed deep-rooting habit of apple trees is also apparently 
over-estimated. This is true of many places here in the east, at 
any rate. As shown later, in a study of 28 trees of different varieties, 
in different parts of Pennsylvania and on various soil types, we 
found that the great majority of the feeding roots were in the surface 
foot of soil, and only rarely were they found deeper than 18 inches. 
This condition apparently does not hold for the more arid regions 
or possibly for some of the looser and dryer soils. But for most 
eastern soils, where the moisture is usually sufficient for satisfactory 
growth practically to the surface, the feeding roots evidently seem 
to prefer the upper layers of the soil. In all trees examined by us, 
at any rate, these roots were comparatively shallow. 

In regard to the high water-content of apples, it is true that the 
fruit averages about 85 per cent, of water. 1 But it is also true that, 
in the remaining 15 per cent, of dry matter, more pounds of actual 
plant food are removed in an average crop of apples than in a similar 
crop of wheat. 2 In addition to this, considerable quantities of plant 
food annually are locked up in the wood of tops and roots and in 
the leaves, which are likely to be blown away and mostly lost to the 
orchard unless special precautions are taken. 

The Mineral Constituents of Apples. 

A fairly exact knowledge of the composition of the fruit and various 
vegetative parts of apples is evidently highly desirable from many 
viewpoints. It informs us as to where (he various plant food elements 
go, and hence what parts their lack or addition is most likely to 
affect. It should thus be useful in diagnosis, in detecting mal-nutri- 
tion in the orchard, and in observing and interpreting the results 
of plant-food applications. Coupled with a knowledge of the approxi- 
mate annual weights of fruit, wood and leaves produced by a mature 
tree under average conditions, it also enables us to determine fairly 
accurately just what is the annual draft upon plant food exerted 
by such a tree or by an acre of apples. 

'As found later, it Is about 8!.C per cent, on the average. See Tables VII, XVII, and 
XVIII on this point. 
a See our Table XXVII for data on this point. 



422 ANNUAL REPORT OF Off. Doc. 

Addressing ourselves to this problem, we first collected a few of 
the more prominent reports of analyses for comparison. Such marked 
differences appeared, however, and such important omissions fre- 
quently occurred in a single report that we decided to give some 
special attention to the matters involved. 

AVe therefore collected all the available analyses of apples, — fruit, 
twigs, leaves, wood and roots, — of which we could find any trace. 
The American and German results were most satisfactory, both in 
number of analyses and number of men reporting, and hence our work 
was confined to them. Most of the American analyses, in the form 
originally reported, are given in the following tables. The wide 
diversity in bases of calculation, sometimes two or more bases being 
used in a single report, made it necessary to recalculate everything 
to a uniform basis, before comparisons or averages could be made. 
This we have done, reducing the original data first to the green 
weight and then to the dry weight basis. The latter basis is pre- 
ferred and used in all our subsequent computations, but the green- 
weight tables are also given. 

In handling the German results, only the final averages are given 
here, together with the names of the analysts and the references 
to their original data. Since their estimates of annual draft are in 
the units of the metric system, we have given them first as they 
occur in the original, and then converted them into English units 
for comparison. 

A number of the American and German reports are not included 
for various reasons. 1 In such cases there were important omissions, 
making it difficult or impossible to reduce them to uniform bases. 
Others were not attributed to any particular work or analyst, and 
were apparently sufficiently covered in the definite reports already 
incorporated in our tables. Still others were evidently abnormal, 
a fact which frequently became apparent, however, only after calcula 
tion to the common basis and comparison with the majority of other 
analyses. Where this abnormality affected only one or two items, 
the reports have generally been given with the affected items inclosed 
in parentheses and excluded from the final averages. 

The Composition of Apples: American Analyses. — The American 
analyses of apples are presented in Tables VI to XilV. Tables VI, 
IX, and XII give the data on fruit, leaves, and wood, respectively, 
as originally reported, with the exception that averages have been 
made by us where two or more similar analyses are reported by 
the same man. Tables VI T, X, and XT 11 show the data in their 
preceding tables recalculated to a uniform basis, that of green 
weight. And Tables VITT, XI, and XIV show the'same data reduced 
to the uniform basis of dry substance. 

'These omitted results include reports by Hilgard (Oal. Bui. 88); reports in the Handbook 
of Experiment station Work (Bui. l.l. o. E. S. ». 402): renorts in Wolff's Vsehen-Analysen: 
also those by Czapek in Biochemie der Pflanzen IT: 830, 1905; and some of Krinig's results in 
'^emie der Mensehliehen Nahrungs-und Genussmittel. 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



423 



5-1 

o 
c 

5i 

© 

© 
© 

5-. 













^ :fit£ 









8S83 || 









t£$£!£5 



eg j-oOi 



rl - r M H 

n g _a> a) jq 



Sj« 



8? 



<-> £o ft 



Is 






Oa> 
O 

HiQ 



t-" 1 - 



..2 ^> <>i "5 « es 
» * OJ! m . 0> I* 

2? >- Ss x: «J £ 
®J5 ° S *> w oo c5 

« p 73 >> „>- • 

© 5 '-3 

oS u «ro3 

^ W 3 3 «M t*> ^ 

Sh C Uo Oij'g 

■Or 



•w m hS a m 
aj-g'-' £»>»«, «£hS 

« a fin 1 " 

es O « .C — <D • ~ *3 



424 



ANNUAL REPORT OF 



Off. Doc 



o 
o 

E-i 

© 

Rs 

o 
© 



O 



II 



:SS88 



o*? 



9, & 



> Sh S 



* * 



"> 



65 to C> *0 <N cc 



38 eo S§ 8 « co Sfj 
§0 oo* oo oo oo* 



£OOt£«a 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



425 



61 

O 
© 

E«i 

>*H 

© 

© 
© 



S 
H 
S 
^ 



(3 

En 



1* 



^ 



SSE 



OOrlHO 



cv 3 co to S K06 

mSmhmhh 



fcS 



ON9 St-O 
n -*' tk' CD ■*' M ■*" 



35888388 -o 



_T 1 ^ 



"ri ° «>" 



^J <u- 






O) - 



.43 .j'os;' 



3§ 






SI 



2° 

CD S 

3 _. 



CS 1 

4) 



■0 2 



a 2 



42C 



ANNUAL REPORT OF 



Off. Doc 



5£ 

-Tj 
-T] 

O 

o 

© 

© 
© 



* 



H 



^ 






^^ 



as 



££££>£&& 



■*flJCO-*HOH 
CX° 1-1 



ifisSaS^fi^ 



-* ffi 5 o5 eft co S 



05 c- 10 <36 t- O 




win 



ggggggg 






cu 55^-5 a 
r-o||«« g 

ca c3 O o cd ro ^ 
00 x 03 OS > > I? 



£ 43 



a £ 



o*3 



o O 



8« a 



flag 

ft M (g CU 

XI <u • - 

~ — ' t>- CO 

|> CU 

^§*° 

O on 

g & «l 

&§a§ 

"t|e>i cu ft 

cu"" a _, 
>h a *> 
11 £.0 3 



co,a 4 - > co 
"* -+J _, O 

^ "X3 



■° a. 



£h P" >» cu 

a HO 



H oi+ 



E ,&S 



SR 


■a 


P3 


&« *"* 


03 




ft_ - 


CO 


l» 


« s 






WW 












03-. 


a 




13 aj 


a 




u) H 


03 


X 










O 




OO 




sz; 


rt « 


& 


w 



8 S 

03 ^j 

ft ~ 

O 
cu 

IN J 

. CD >CC 

' J3 O) ^ 

3 <u 

.SCS£ 

cu 

03 •'-s 

"ol^fs 
■O • cu 

»?? 



No. 20. 



PENNSYLVANIA STATE COLLEGE. 



427 



2Q 

a 

o 

© 

o 

o 
© 



to -c 

s i 









o 






fcS* 



38 



OJ O* Cfc ift "3 CO 

>o n f £i H :o ■* < 
oa :o 'O Oi :c co i 



f lOQOO 

tea 3: cs co t~- 50 

CM -HW 'OH 



**- CO 

t^ yj ^ 6 S S a 



(. J O ■* -f fl 



3 Moo 

.wo tc« 



3TJ-; ^ 
£oSco 








s 


1 1 1 1 1 1 
1 1 1 1 f 1 


O 






8888S8 




u 

O 








: : : 1 


£ 




J3 








! ' ' CO 

: r :8 


aS 

•~ SO 












o 


j 




' 
• si a> o 


is 

hod 












4 


imders, 
imders, 
berts, . 
berts, . 
n Slyke 
D Slyke 
arren & 


hi g 

" so 






a 


& 


!§>>£ 







428 



ANNUAL REPORT OF 



Off. Doc 



cc 




eq 




^ 




^ 




&q 




^ 


g> 


Kl 


a 


•^3 




^ 


fl 


Rh 


Cfl 


^ 


& 




-o 


Bh 




o 


m 


^ 


a 


© 


oi 


1-1 


Si 


Eh 

►*H 


o 


© 




fts 


3 


^a 


9 


© 


oa 


© 


>, 










bq 


a 


tei 


a 


Eh 


a 

CJ 


1 


E 




a> 




H 


►-H 


H 



H ~ 



Eh 






1* 



*c£ 



S# 






fc* 



CO CO 

00 -* 



(- (^ lO tft 00 CO 

r Oi ic 55 1> oo 



cr en ■** o o ©I 
cc ■* -* eo ci -v I 



>T l.ft 00 Q_ 1 Ci CO 

C oi 5 oo ^ ~* 



3 SS^s t^ 1 

l> ft iri cp in a> 

cm co -* o -* co 











9 




















/-S^ ^*N 




> 


sl -2g 

*"' ^ e»«05 . os 


O 


bow » 


t» ; 




>>~ >• 




ti 


^3 ^c 


■D 


10 US 




a 






3 






fc 








888888 


& ! 

■o ! 










O 






o • 


A 








3 




al."," 
al., 

rhees 


^ : 


•1 




.9 sv 


o 




■«*>§ 


00 9 

CJ 03 


«a 




i""** 






to" to" J 






t> 03 


3 


73 T3 SCCCC 0J 


<! 


a a 

3 C 
03 « 

oca 


Robe 
Van 
Van 
Wan 








U CD 

2 03 

*«, 
.03 

8 •°' 



IS! 

si's u 



ft 2 to 
"> o 3 

C -I. OJ 
.•°-3 

■SS S 



43 "03 
^ * <s 

V 0J ™ 



• 03 



I 



£■&£ 

£~ 03 

•ogn 

3"0 

g~a 

Safe 

03 03 cu 

--I 

03 O 

rt0< a 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



429 



o 



3G 


s3 




^ 


>~ 




-»*. 


T 


= 




^ 






a 


hq 


o 


hq 


a 


ft, 


a 


ft. 


3 


^ 


o 


^ 


B 


© 


<a 






< 





C 


o 


H 




0Q 


03 


O 


m 


^ 


bg 


~-. 


>> 


© 


B 


© 











rHro 



8 



ye 



si 



6£{£ 




£ s£sS 



s sl 



£ fcS 



£ fcS 



.-I SO 

O r-l 



00 



«2~ £d£-2 £££,-; 

6 SB s s afe,'° £ 



5 %*£«% 



« £ fee 

w 5aJ 






0X*2 



t£-= sSfc?fc9 



^ 












u: 




t* 


fc 


ai 


0) 






3 


3 


fe 


g 



3~ no 

O fc oc 

SoxC 

03 0> CI 



'« *1 



f OX >» 



rt SM 

C2 2 



rH rH IA 



£888 g"88 



oj S 

3 1 



— i s C 

a S^ 
ah £ S as 25 



°s 'S ■£ * 



rH a) ■ 



;_by a> 



-«-. a 






a a 

. a a 
8^ a 



2 « r„ n 

X3— ■ OX S-. 

g 53 03 



3«S 



£ §33 o 

» [> QJ Q_ 

_ O « a> 

§*£ K 

.Ens • 

ill * 

o C5 ^ 

►h OX « 

EH - Z «j 



Safe 

1-1 _ O) 

■ 5ST3 



a 3 
« o o 






| I |~ 

a ocgW 

5 o • o 



g*» • . 

CB 08 CO Q, S 

oggSa" 



430 



ANNUAL REPORT OF 



Off. Doc 



C 

c 



^— In 

rr « 

| i 

§ I 

§ 9 



S 

H 
H 



B 

6"! 



< 



o 

bOvO 



08^ 



£&- 



•"is? 



SS3£8 



15 ^i CO S Cr 



to to 



00 c* ^ oo 

(OM!OM 



i CO -* -* "^ 



'S'SL.O J* *s"g*0 SS 

-, 9 3*0 Ov *"** ° ^ *- 
^ 3 3 " a? bo v„ £ o 

1-1 tJ * 0"7! ra 1 — bo 
C,'-' ft «> 



SiHioinoooococoipiot 
Oi0500>ppppp< 



££««.S 



jz,;^ 0) oi o 

- . . > 



*c .£ 



£1 

,0.0 






& s a) «^^=3 s e 

n n to be t» >. > bo 

llgggS* 



.SJ -a 

* O 



"O O 



*• e- 



bci-i 



OJ.C 



:. 2 r 



r ->- 



61. 






-M > qj *>> o> 

g'Sig.gS 

o -J C 
0> OS 03 a 

-S3 * 

S «s H>a 

_ «*> 



P.S 



•°a « *- H 
*> 3 ®*0 _ 

0> O P+i 

£ -.S a „• 

«e.J2*o «~ 

r-i O. (-< oj *^ 

.2 boo £ a 

•P a fc. m 

co~~ u 

**-* 2 03 OD 

„ a +-. a) en 

H « ^M — 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



431 



© 
© 

© 

© 

>-*■ 

S 

a, 

© 



© 

g 

© 

Oh 

© 
© 



N 



5^ 



J3 








< 


00 -V 


*# 


CO CO 



3^ 



o „ 



2^ 



■:■: to 



ICOOS CJC 



r-J Ot t£> ■-. 

tO Ol © 05 tO 
rH rH rl 4>J -*H 



£23 

04 Ci tO 

co cvcv 



a^ 



• 1-4 Ifi 

• IOCV 



eo co o.' © 

O) 01 -^ 10 



o a 
gig 

So 

.O c 
<o 03 



00 ^ ft ■*£ 03 >»~^ .* 




ois 

a g 



«- a 
<o o 

p 

5» 



31 



432 



ANNUAL REPORT OF 



Off. Doc 



Meaning of Variations Observed in Composition. — In the preced- 
ing tables, i. e., those which have been reduced to uniform basis, it 
will be noted that, while in general there is very good agreement, 
yet there are some rather marked variations. Some of these are 
doubtless due to manipulative or experimental errors. It is to elimi- 
nate these, in so far as possible, that we have resorted to the method 
of averages. 

But aside from this, some of these variations are undoubtedly con- 
nected with actual differences in composition of the parts at the 
time of analysis. These differences may be partly due to losses with 
increased maturity or age of the parts. Such losses are very likely 
to occur, in the case of leaves especially, when permitted to remain 
on the trees until full maturity before analyzing. 1 

But another and an important part of the observed differences in 
composition is to be connected with evident migrations of mineral 
constituents from Ihe older parts to the younger, and from various 
vegetative parts to the fruit. In connection with the former point, 
in Table XIV for example, if we compare Roberts' composition figures 
for the old tree with those of Van Slyke for the twigs of similar 
mature trees, we find a very marked increase in the latter. 

In the elements reported, the twigs run from 2 to nearly 3£ times 
as rich as the average for the whole tree in Roberts' figures, which 
of course include the twigs and smaller roots. The same general 
relation appears in the German averages, shown below in Table 
XVII, for trunk and limbs as compared with fruit wood (Fruchtholz), 
the latter being about twice as rich as the former. 

This relative richness of twigs as compared with wood, indicating 
a migration of ash constituents from the latter to the former, is 
also very strikingly shown in the peach. This may be seen in the 
following table, No. XV, from results reported by Warren and Voor- 
hees. 2 



TaUe XV.— RELATIVE COMPOSITION OF 
WOOD IN THE PEACE. 

(New Jersey Results.) 2 



OLD AND NEW 





N. 
% 


P2O5. 

% 


K2O. 

% 


CaO. 

% 


Season's twigs, .„ 

Trunk and branches, .__ _ 


1.32 
.28 
.82 
.43 


.34 

.11 

.27 
.09 


.54 
.15 
.31 
.25 


1.73 
.33 


Rootlets (under 1 inch 




.61 


Larger roots 




.34 









As shown in this table, the neAv twigs were from 3 to 5 times 
as rich as the old wood, with the small roots 1} to 3 times as rich as 
the larger ones. In the peach tree examined, the new twigs are 
reported to have contained about one-fourth of the plant food used 
in the wood growth of the year. 

On the second point, — the migration of mineral elements to the 
fruit, — we would call attention to an interesting relation existing 
between size of the fruit crop and composition of leaves. From 



ifiee article by LeClerc and Breazeale in U. S. Year Book. 1908. pp. 389-402. 
2 Warren and Voorhees, J. A., New Jersey Experiment Station Report 1906, p. 201. 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



433 



present evidence, (he ash-composition of leaves is much lower on 
trees with fruit than on those without fruit. A hint of this may 
be seen in Table X, in comparing Roberts' figures for the two trees. 
The thirteen-year tree had no fruit in the year in which the leaves 
were analyzed, while the older tree had apples. Although there 
are too many other varying factors for a good comparison here, yet 
it will be observed that the leaves of the tree without fruit averaged 
nearly twice as rich as those of the tree where fruit was present. 

The best analyses that we have discovered bearing on this point 
are again to be found in connection with the peach, and are reported 
by Warren and Yoorhees. These are shown in Table XVI, which is 
derived from page 200 of the New Jersey Annual Report for 1906. 

Tabic XVI.— RELATION OF LEAF COMPOSITION TO SIZE OF 
CROP IN THE PEACH. 

(From Results in New Jersey.) 



First 4 years (no fruit). 
Five years (with fruit), 
1904, 8th year (no fruit), 



N. 


P2O5. 


% 


% 


4.09 


.70 


2.67 


,55 


3.09 


.06 



K2O. 

% 



2.12 
1.42 
1.80 



These figures, being averages for several years from the same tree, 
are doubtless quite reliable. They show that evidently a very con- 
siderable transfer of materials takes place from the leaves to the 
fruit in crop years. The same is true of the ash of apple, plum, and 
pear leaves, as indicated in the analyses made at the New Jersey 
Station. 

It is probable also that the twigs act similarly to some extent, 
as storage organs or sources of mineral food supply for the fruit. 
But apparently no analyses bearing upon this point are available. 

Herman Analyses of Apples. — The average composition of apple 
fruit and vegetative parts, as determined by many analyses made 
by leading German chemists, is shown in Table XVII. Only the 
averages are given in this case. They are derived from analyses 
made by Dr. Barth, of the Colmar Agricultural Experiment Station ; 
Doctors Steglich and Richter, of the Dresden Station; Dr. Edward 
1 Totter, Graz Station; Dr. Richard Otto, Laboratory at Proskau; 
Professor Karl Reichelt, Friedberg Laboratory; and Kbnig, in Chemie 
der mensehlichen Nahrungs- und Genussmittel, I: 823, 826, 828 and 
832; and II: 959. 

For the other original data and references, the reader is referred 
to the article by Steglich on Statik des Obstbaues, in Arbeiten der 
Deutsche^ Landwirt8chaft8=Gesell8Chaft, No. /.?,?.- 1-147, 1907. The 
number of analyses considered in obtaining the averages for the var- 
ious parts, and also the analysts making them, are indicated in each 
case. 

- The "static values" included are the estimates of Steglich, used 
in deriving his system of Statics of Fruit Culture, which is discussed 
more fully later. 

28—20—1910 



434 



ANNUAL REPORT OP 



Off. Doc 



ft. 

ft 

O 
Ex 

S 

Sb 
o 

&q 
^b 

O 

o 

SQ 
O 
ft 

o 
c> 

I 












moo 

S3 



o 



■* c- cu o* 
■Asa £-■* 



"3^ 



^^ 



D 
99 



S§S§5S 



^H <3i CC CO 
CO-* 00 IQ 



'3S?S8 







o 3 



■ijcQ 



com P8 



a3 



<<Jc» 



(X) , 



flgt» 



S2- 



C3 QJ M 

o >-, o 
•2~fr 

S3 

9fl» 






OB •£ 



_CO 



as 

'.si 



"a 
" fa" 






a a 



JjjM 






.9 .n O O 
J3 'cS 'S *"• &A 

■*->" ad ■ 

-■a 2 

§ BOS >> 

p» 03 -£,Q 



s$sy» 3 



•c — 



oj'S'a^ 

*-< a* 03 ,-^-~- 



a 

<P o 



09 

*"* Ul 02 

ft o> o> 



3>« £ 

1 >>5 



2 "3 "3 2 o3 ^ "s 

03 a a as a g _ 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



435 



Vl 




ton 




o3 




u 




a> 




> 


kx 


03 


•-H 


d 


b 


05 


fti 


a 


Bh 


u 




<v 




O 





0) 


fe; 


xi 


tH 





so 


p 


Eq 


k ~ 


^ 


1— 1 






^ 


^3 




d 


^ 


03 





HH 


o 


M 


o 




t^ 


M 


i— 


l—i 




1— 1 h- 1 




L^ |_H 


kj 


^ l-H 


q 


02 ►> 


&H 


0> k> 


as 






d ~ 


o 


• rt 4> 








T3 .O 
0> 03 


fei 


£& 


o 


£ bX 


&H 


-a d 


H 


bxi o 


U! 


© 

&H 


03 «w 


© 


<D Of 

► -3 


o 


o3 +■' 




d.a 

03 cS 


Hi 


S o 


1 


2 g> 
<j p 




?H 






K3 


o> ri 


>-l 


■+-' r— 1 


cq 


ton os 




dH 


•9 S 




-O -fH 




a f> 




o £ 




O o 





1 


in m 
coco 


StO 


com 
11 


coco 


00 00 


<N CM 


cB 
















O 








fcH 










<N 


t- _ 


& 


s* 


CM 

88 


ss 


*S3 


P-H 










H 


J 


ri 


MB 5 : 

3 


| 

CM O* 


iftira 


c§ 

is 










CO 


g 


! » 


3* 


CO 

too 




88 


i 




IO 


1* 






<m 


oo 


s* 


COCO 


coco 


i-t rH 




CO 


H 


M 




So 


in 


Sn 




Ol CM 


i-Ht-l 


9$s 








Ph 










& CM 

ID CO 




o*eo 






■* -<x 


K*^ 




■N(N 




aj 


£ . 


in 


CO -* 


>> CS ~ 


C* tt 


-* ■* 


in in 


IQIO 






3 








t» 










1 




i i 




fOt3 


aJ a 


11 

PhPh 


















CO 

CD 


CO 


% j 




bo 




SI 




ea 


bd 


CS i 




M 


03 


U 1 




CD 


N 


CD 1 




s* 


<u 


> 1 




cs 


C3 


* I 




a 

« a 

§1 


1 B£ 


r A ! 




cu +. 




CU ! 




O K 




a ; 




"S* 


E 
1. 73 C 


, S i 




§•£ 


° £ 


S : 




c 


> i 




a c 


' a c 


' a : 






1 .2 E 


CS , 

! S ! 




fee 


> fe c 


> S : 




!« 


) Sc 


> M ' 




•«s- 


<" 


< . 




<w^ 


3 ^.-C 


5 -""2 




oS 


J oS 


i oS 






3 ; 


3 3 




CO " 


(U 


CD 




cs < 


i cs c 


3 cs S 




tl : 


3 ir! : 


I gg 




<u £ 


* cu ^ 






> « 


3 t> c 


3 t»« 


i 


< 


^K 


< 


dts 


* < 


o 



4:13 ANNUAL REPORT OF Off. Doc 

Founded as it is upon the large number of analyses of accurate 
men, whose personal equations are doubtless eliminated by the method 
of averages, this Table XVIII should come nearer the actual average 
composition of the parts considered than has been done before. For 
the same reason, it is probably a closer approximation of the true 
composition of apple fruit and vegetative parts than we have for any 
similar woody plant. This is because the reported compositions of 
such plants are usually based on relatively few analyses, and single 
analyses, as we have seen, are subject to quite wide variations. 

In the values adopted for our later computations, we have tried to 
be conservative in all cases. Whenever any deviations have been 
made from the averages they are either reductions or are toward the 
side of preponderating evidence. 

The relatively high plant-food content of the leaves, and the marked 
differences in relative demand made by the various parts, are quite 
noteworthy. But this is in harmony with observations on other sim- 
ilar woody plants! It may also be noted that from the work of 
LeClerc and Breazeale, referred to later, 1 the percentage composition 
in the ash of leaves, may depend to some extent on the rainfall, and 
that it is quite possible that the ash requirements might be consider- 
ably in excess of the ash actually found in leaves that had been washed 
frequently by rains. 

Annual Weic/hts of Leaves, Wood and Fruits, Produced by Mature 

Apple Trees. 

With the composition of various parts fairly settled, the next 
stage of our process is to determine the approximate weights of these 
parts annually produced under satisfactory orchard conditions. 

This is readily done in the case of the fruit. For it we have de- 
cided upon an annual average of about 14 bushels, or 700 pounds, 
per tree for the mature orchard. This is less than half the weights 
we have secured in single years from mature experimental trees, 
1,500 to 1,600 or more pounds per tree being not infrequent among 
the trees of our Experiment 221. Many individual cases are also 
known with crops much higher than these. On the average, however, 
a fruit production of 700 pounds per tree, which makes 490 bushels 
per acre of 35 trees, may be considered a satisfactory return for a 
good orchard. 

When we come to determine the average annual production of 
wood and leaves, however, our evidence is far less clear. The data 
which we have are shown in Table XIX. 

1 LeO!erc and Breazeale. Plant Food Removed from Growing Plants by Rain and Dew. 
IT. S. Department of Agriculture: Year Book, 1908: 389-402 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



437 



Table XIX.— OBSERVED WEIGHTS OF LEAVES AND WOOD 

OF APPLES. 

(Average weights per tree.) 



Author or Observer. 



Leaves. 



Wood and Roots. 





1 
1 
2 


13 
"old" 
30 
37 


33.18 
232. 

80.52 
99.2 


17.26 
92.51 
34.72 
28.79 








5251. 4 2 
(7.035) 
111.1 


2951.22 


Van Slyke et al, 3 - 


(3.685) 


Steglich 4 (X2) , . 


54.35 














111.1 


43.32 


108. 5 


56.68 











l . Cornell Bulletin 103: 534 and 538-40. 1895. 

-. These are total weights of wood In one old "Westfleld tree, said to be below normal 
in size. 

3 . Van Slyke, Taylor and Andrews. Geneva Bui. 265: 209. 1905. 

*. Statik des Obstbaues, p. 95. The values are taken for trees with trunk-girth of 119 cm., 
such as are found in our experiment 221. Steglich's figures are reduced to English units and 
doubled for reasons indicated later. 

6 . In getting these averages, Roberts' wood weights are divided by 50, on the assumption 
that they were capable of being produced in about 50 years of mature tree-growth, and the 
quotients are averaged with Steglich's estimates. Van Slyke's wood weights are excluded in 
deriving averages, Bince they are only those of the current season's twigs. 



The sources and details of the data shown here are given in the 
footnotes. *In Roberts' figures, the leaf weights of the old tree look 
rather excessive, but they are fairly well offset by those of the thir- 
teen-year tree, which are evidently low. The wood weight found 
in the old tree is the total made during its life. Since it is said to 
have been below normal size, we have assumed that it would have 
been produced by HO years of normal mature tree-growth, — doubtless 
a safe assumption, — as others have considered it "growable" in 45 
years. 

In Van Slyke's figures, the wood weights given are only those of 
the twigs of the current season. The new wood of the roots, and the 
wood of annual increase in thickness throughout the tree are not 
included. 

It will be recalled that in Warren's findings in the peach, the new 
twigs contained about one-fourth of the total plant food of a year's 
growth, and were from three to five times richer than the general 
wood of the tree. On this basis and also on the basis of the other 
observations on apple growth, it is probable that Van Slyke's twig 
weights should he multiplied by about 15, in order to give a fairly 
close approximation to the true annual wood production. It has 
seemed better, however, in this case, to exclude them in making the 
final averages. 

Steglich's estimates in the original are given in kilograms per centi- 
meter of trunk-girth. In getting his particular estimate for this 
table, his figures for trees of 110 centimeter trunk-girth, such as those 
in our Experiment 221, were reduced to English units, and doubled 
for reasons explained later. 



438 



ANNUAL REPORT OF 



Off. Doc 



Some corroboration of the average secured in Table XIX is ob- 
tainable from studies made on the peach. For example, it appears 
from the data on page 218 of Geneva (N. Y.) Bulletin 265 that an 
apple tree takes up about 2^ times as much plant food as a peach. 
It is also shown in the same bulletin that the composition of the 
two trees is not materially different. W(ood and leaf weights found 
for the peach, therefore, multiplied by 2^, should give us an approxi- 
mation of the similar weights for the apple. Such weights are given 
in Table XX. 

Table XX.— OBSERVED WEIGHTS AND ESTIMATES OF 
LEAVES AND WOOD IN THE PEAOH. 

(Average weights per tree.) 











Leaves. 


Wood and 


Roots 










.0 


























Author or Observer. 


a> 




. 






. 










44 




^j 










■ 






o 


>, 


a 




j= 


is 
a 




B» 








a> 


3 




>. 






>> 
















H 




u 






sz; 


< 


a 




6 


o 




a 



Warren and Voorhees 1 , -. 
Warren and Voorhees 1 , -. 
Average per year 2 (8 yr.), 
Van Slyke 3 , 



Rough estimate for peach, 

Derived estimate for apple (peaeh X2J) 4 , 



21.31 

45.75 



40+ 
100+ 



316.2 

39.S2& 
12.833* 



50+ 

125+ 



1 . N. J. Station Annual Report 1906: 192-204, Table V. The weights given are the totals 
for ten years. 

2 . The 10 years' growth is equivalent to not over 8 years of mature tree growth, since the 
first years' growth produced only about 1/40 of the amounts averaged in the last six years, 
with the second year producing i, the third, 2/3, and the fourth year fully these amounts. 

8 . Geneva Bulletin 265: 211. Weights averaged by the writer. 
*. Reason for multiplying by 2i is explained above. 

These weights and estimates are evidently only approximate, so 
far as conditions in any given orchard are concerned. In the case 
of the New Jersey results, for example, we have assumed that the 
total weight found could have been made in 8 years of mature tree- 
growth. It is probable, however, that G or 7 years would have been 
ample, since the tree studied evidently did not do as well as the aver- 
age trees in their orchard, its fruiting being less than half that of 
the "latter. This shorter period would naturally increase the yearly 
averages calculated from their results. 

Van Slyke's leaf weights are evidently satisfactory, being the 
average from three trees during one season. His wood weights, 
however, are again unsatisfactory, because again they represent 
only the current season's twigs. They therefore probably do not 
show more than one-fifth of the actual annual wood-production, for 
reasons stated above. 

On this assumption, together with the actual weights shown in 
the New Jersey results which are evidently low, the estimate of 
50 pounds of wood produced annually by a mature peach tree is 
probably at least not excessive. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 439 

The derived estimates for apple trees correspond very well with 
those of Table XIX. On the basis of both tables an estimate of the 
annual production by mature apple trees of 100 pounds each of wood 
and green leaves seems to us to be approximately correct, and at 
least not to be excessive. These are the weights that we have used 
later in our computations of annual draft on the soil. 

The Annual Plant-Food Requirements of Mature Apple Trees. 

Various attempts to answer this question have been made in the 
past. Of these, by far the most elaborate and comprehensive is that 
of Doctor Steglicn, of the Dresden Station in Germay, to which we 
have already referred. In an article on Statics of Fruit Culture, 1 
published in 1907, he has developed a very complete system lor esti- 
mating the annual weight increase and manurial requirements of 
individual trees. In his system, the trunk circumference (Stain in 
umfang) is used as the determining factor. The plan is developed 
for the pear, cherry and plum, as well as for the apple, and itjs 
based on a large amount of tabular data. 

The data show: (1) The weight relations of the roots, trunk, 
branches and leaves;- (2) The annual increase in growth; (3) the 
annual leaf and fruit production and their relation to the trunk 
circumstance; and (4) the chemical composition of the vegetative 
organs and fruit. A large table is given, showing for the wood, 
leaves and fruit, of the fruits named above, their estimated content 
of green and dry substance and their mineral requirements, for each 
centimeter of trunk circumference from 15 cm. up to 150 cm. in most 
cases. 

To test this system of Steglich's, we have applied it to the trees 
of certain of our experiments whose average trunk circumference 
was known. The results are given in Tables XXI and XXII. 

1 Steglieh. Statik des Obstbaucs. Arbeiten der Deutschen Landwirtschafts-Gcscllsclialt, No. 
132: 1-147. 1907. 



440 



ANNUAL REPORT OF 



Off. Doc 



B5 
ft, 



O 

c 
o 



-t| 
Oh 

O 

o» 

Bq 



ri 



a 
5> 







CO t- 00 CO 
CI (*- r-t 00 




d . 

a be 
O 


gas's 

HH(NM 






CO <>* iO<N 

00 00 o* ^ 




6 ■ 

ci So 


109, 
124, 
324 

405 






°° "5 s. 1 is 

rH -* Ol to 




O si 


uj ej ih a 
Ot 00 c-oo 




£ 








co -t* oo 

C- lO ic o 




& '* 


>6 vice's 
ou 35 op oa 




o 


3358 




=1 
CO 


rH* Co <M* © 

rH rH CO ■<* 




Green Wt.l 
Kg. 


©W[^ 




0*> »o >c: i-h 
•* irfi •* cc 




Average 
Trunk i 
Circum. j 

cm. 


S^feS 






2S£j£5 












i ■ i 
lift 

J 1 .02 




0) 


rial, 

Northern 




> 


York Impe 
Jonathan, 
Baldwin, 
Baldwin & 










V 

id 

s 

3 

55 






Experiment 


C£ C£ 00 JH 



os5 



fcsa 
o 

w 3 

cs 

.2 



£2 

Sang 

3>C 



0) 3 

as 



•° s 

25 



■S B 

O a 



ass 
h-3 



N., 20. 



THE PENNSYLVANIA STATE COLLEGE. 



441 



!*3 
f^ 

&h 
&i 

Oh 

&H 

o 

&h 

o> 

&H 



H 



- — 



>SJ£ 



9- 










» rH U$ Ci 



CO •<*< ^ 36 

so f-^ oo « 



HIOOH 



O0CSK5 © 

ssss 



CO CO© b- 
CO 00 ■-! o* 

ooooV 



rtrtCtM 



& . « 

a a - 
,3 go a 

-^ ^— — '. 
t. c— — 
O o a ~ 



nrt«« 
(N 0* CO CM 



2 3 






22 
3* 



■a" 



•M.C 

us ■" 

S SB 



■n a 



— D 

Is 

3« 






-5 






°ls 



£=s 



o a; 



442 



ANNUAL REPORT OF 



Off. Doc 



Before passing judgment upon the accuracy of these estimates, we 
will look at those of another eminent German chemist, Doctor Barth, 
of the Experiment Station at Colmar, Germany. Barth's calculations 1 
of the requirements of various fruit trees, including apple, cherry, 
peach and pear, were made on the basis of some 90 original analyses 
of vegetative parts, supplemented by collated analyses of fruits, and 
by researches on the growth of wood, leaf and fruit. In his calcula- 
tions, the individual tree requirements are based upon the area of 
soil covered by the tops. His final estimates for the fruits named 
are given in Table XXI II. 

Table XXIII.— EARTH'S ESTIMATE OF THE FERTILIZER RE- 
QUIREMENTS OF FRUITS. 

(Stated in grams per square meter of area covered by tops.) 



N 


PsOb. 


gm. 


gm. 


7.1 


1.5 


7. 


2.3 


7.5 


2.1 


11.9 


3.1 



K 2 0. 

gm. 



CaO. 

gm. 



Apple, 
Peach, 
Pear, 

Cherry, 



7.30 
10.63 
10.90 
15.95 



9.80 

8.42 

6.70 

21.05 



The general formula which he derived from these figures is: N, 
10 gm. ; P 2 5 , 5 gm. ; K 2 0, 15 gm. ; and lime, 20 gm. ; per square meter 
of area covered by the tops. 2 Disregarding this general formula, how- 
ever, and applying his figures for the apple to the trees of our Ex- 
periment 221, which had an average top diameter of about 9 meters 
in 1910, we obtain the results shown in Table XXIV. 

Table X XIV.— BARTH'S ESTIMATE OF THE ANNUAL RE- 
QUIREMENTS OF APPLES. 

(Applied to our experiment 221, and to acres partly or wholly covered.) 



Amounts. 


Age of 
Trees, 
Tr. 


Area Covered 
by Tops. 


N. 


PbOb. 


K2O. 


CaO. 


Per acre (35 trees), 


37 
37 


63.6 sq. meters,— 


451.68 trni. 
34.851b. 


95. 126 em. 
7.36 lb. 


I6I.1 erm. 
35.821b. 


623.45 gm. 
48.1 lb. 










100% of acre, 


63.34 1b. 


13.381b. 


65.13 1b. 


87.44 1b. 












78.2% of acre 3 , _. 


49.531b. 


10.46 1b. 


50.93 lb. 


68.371b. 


square?, limbs 
touching. 







1 . Barth. A Progress Report on Investigations of Fertilizer requirements of Fruit Trees. 
Gartenflora, 48, No. 5: 125-126, 1899. 

2 . The large amount of K»0 was included to provide for the cherry: nnrl thp PeOb content 
was increased beyond the yearly requirement because of its slow availability. Among other 
interesting things, his analyses showed that the ash of the pits of cherries and plums is 
largely P2O5, and that N is present in considerably greater quantities than the ash. 

3 . This is the relative amount of an acre covered by trees exactly circular, just touching 
at the tips of the branches, and set in squares. 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



443 



The first line of this table is derived from the data of Table XXIII 
as slated above. The others have been calculated from it, reducing 
the estimates from grams per tree, as shown in the first line, to pounds 
per acre, for the different ways indicated of estimating an acre. As 
compared with Steglich's estimates for the same trees, — those of 
Experiment 221, — Barth's range distinctly higher. If the comparison 
is made between Steglich's estimates and those of Barth, as shown in 
the last line, — which is really a fair way of applying Barth's formula 
when the distribution of roots is considered, — it will be seen that 
the latter's estimates average about twice as high as Steglich's. 

By further comparison with other estimates, such as those shown 
in our next two tables, it appears fairly certain that those of Steglich 
should in general be doubled, at least so far as the annual draft of 
plant food is concerned. This of course does not mean that Steglich's 
is not valuable; it merely shows how to use it. As a basis for estimat- 
ing the particular quantities required for a given tree, his system 
is undoubtedly the best. It is even unrivalled, except by that of 
Barth. 1 

There are some minor imperfections in his work, however, which 
have led to the adoption of the low values indicated, and from all the 
evidence it appears that in applying his system to apples at least, 
the values should be approximately doubled. This we have done in 
certain of his estimates tor insertion into Table XXV. 



Table XXV.— ANNUAL PLANT FOOD DRAFT OF APPLE 8, PER 

ACRE. 

(Estimates by American and German Authors.) 



Author. 


No. of 

Trees 

Studied. 


N. 
lb. 


P2O5. 
lb. 


K2O. 
lb. 


CaO. 
lb. 


MgO. 
lb. 


Van Slyke 2 , — 


2 
2 


51.5 

62.2 
49.5 
45.8 


14. 
18.3 
10.5 
13.8 


55. 

S9.4 

51. 

62.6 


57. 


23 


Roberts 3 , - 




Barth 4 


68. 
54.6 




Steglich 5 (X2), ! 












53. 


14.15 


64.5 


59.9— 


23 









The estimate for Roberts in this table is obtained by dividing by 
20 the data in his Table 1!); by dividing by 50 the plant-food totals 
obtained from his tables 12 to 15 ; and by adding to these quotients 
the weights of plant-food constituents contained in a 400-bushel crop 
of apples of the composition given in his Table 4. In Roberts' own 



1 So far as actual requirements go, Steglich's estimates may still be a fairly close approxi- 
mation of the true mimimum plant-food values, since it is well known that a plant regularly 
takes up more minerals than it really needs if the excess is available. On the other hand, 
analyses of mature structures may show less mineral content than is actually required, on 
account of the apparent losses in such structures ;is a result of washing by rain and dew. 

2 Van Slyke, Taylor, and Andrews. N. Y. Geneva Bui. 265: 220. 1905. 

3 Roberts. Cornell Bui. 103: 538-40. 1895. Derived from data in his Tables 12, 13, 14, 
15, and 19. 

*. Gartenflora, 48: 125126. 1309. The estimate here Is that given In the last line of our 
Table XXIV. 

5 This estimate is that Shown in the last line of our 'table XXII, with the values doubled 
to make it more nearly comparable with the others. 



444 ANNUAL REPORT OP Off. Doc 

estimates of annual draft, a 525 bushel crop is used. The estimates 
of the others are obtained as indicated in the footnotes. 

As finally arranged, the estimates of Table XXV show some rather 
marked variations so far as individual elements are concerned. Most 
of these are at least partially explainable, however, and the final 
average should be fairly reliable. 

Our own calculations and estimates of the annual draft of apples 
are sriven in Table XXVI. 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



445 






ft* 

a, 



6q 

a. 

ft, 
ft. 



62 



OS 

Q 

q 
o 
p 



S 
> 








a 


&t ■* ■.'; 








CO 

< • 


Essa 


8 






„X5 
03 ~" 


— I cm' e i 


» 


g 














O 










(n 










• 





i 


T 




9* 


SSi! 


S 






4)— « 










ft 












oooc 
•* in <- 


s 


8 




ga 


^ 


ej 




a 












©CM CI 


** 


. 






ci co <o 

00 00 o 


1 


35 






«tOC« 

1- »~ lA 


8 








00 iC CO 


CM 






9« 


^ "*. *"! 


00 


b 


,_, 


M" 






CO 


a 










+i 






8 




OS 




JOB 


d> 


T3 > 


o« 


O -f 00 


9 




Sao 










a 


ft 








"3 










«? 










S | 




-* © l~ 

cv r-t CO 


8 






. 


CI CO 50 


>Q 


8 




*4 






8 


t* i 










Z 1 











3 


OJ* 




OO 




| 


*l • 


00 


s 


§8 




t, ^ j3 


CJ » i- 




i- 


5 


3 


«~. BO O 




D 


t>> 










■O 


H " 








■a 


c +j 


£S£ 


A 


■d 




<u.n 








3 


£_CJ) 


S8S 


g 


g 


p. 

a 

o 










J 


S 






i 
1 




t. 










S 










H 










o> 










Ph 










■o 










V 




















CO 




















H 






(» 




s 
















c 




w 




C 

ft 


CO 

m 

ft 






"D u ' 


„ 


,_, 






o >a 


CO 


cc 








O 

Eh 


1 









C ?> 









sfr« 



s£ 



-t X 






44C ANNUAL REPORT OF Off. Doc 

The bases for computing tins table are derived especially from the 
data in our Tables XVII I, XIX, and XX, and the discussion follow- 
ing. Our composition figures, derived as they are from the mass 
of analytic data underlying Table XVIII, are believed to be quite re- 
liable. There may still be some question as to the accuracy of our 
estimates of the annual production of green weights, given in Table 
XXVI. But they also are based upon the best evidence at present 
available ; and, all things considered, we believe that the present table 
is a very close approximation of the true average annual draft of 
mature apple trees upon the plant food of the soil. The striking 
agreement between our final figures and the average in Table XXV 
is also noteworthy, and affords further evidence of their accuracy. 

The relative drain exerted by wheat as compared with apples is 
shown in Table XXVII. 



No. 20. 



THK PENNSYLVANIA STATE COIA.KUK. 



447 



&3 
Bq 

ft. 

fcq 



© 

S 

© 

fin 

© 

s 

© 
© 



•*-( 
•^ 












c . 



0.0 



*S 



3 






22 

co' co 



32 



O50S C 

88S 



COOS :o 
-t< 00 M 



OHO 
i-t »Q O 

cics'co 



a is 

03 03 






333 

co 10 «o 



CV * f- 



O « 3 

£3£ 



tsEs 



AAA 
AAA 



a« ■ 

oj 03 1: 
£« 



us 



§ O ' 

3<« 

W> 

° A J. 

5o« 
x-o 2 
• «•§ 

p. m -a 

S e 

5 as 

s» £ 

a g 

oat 
o <» 

05.. 

S«o 

3 - -./ 

S^ 

fc A 
O • 

^ rH ^ 

» -S 
Ss 

i^ a 

lis 

ai y - 

.ft- •" 

Qj — 

SfeCa 

*g» 

gb' u * 
Sot &r« 

rH A 
g - 'O 

*£* •* 
*>.- ti <i>£> 

S « r 

**! • '- 

.jj C3 

"2 a a«'£ 
§ a Sgo 

Is Afe| 

.H N 8 

■jh-O 1 ' a> 
O a) £j 



5 afflu, o 






< S SSO 
. § a S 

"MS •«" 

.S £?"" 



32 



448 ANNUAL REPORT OF Off. Doc 

In this table, Ave have compared a 25-bushel crop of wheat, which 
is rather above the average, with an apple production that has been 
shown to be somewhat below it for good orchard conditions. In 
spile of t his, however, it will be observed that the total draft of the 
apples is greater in every case but one. These figures can hardly be 
doubted, if the amounts of fruit and wood there indicated are to be 
produced, — and these amounts are evidently not greater than every 
good orchardist strives for, — the corresponding amounts of plant food 
must be forthcoming. The parts have the composition indicated; 
plant food can not be created, nor can it be drawn indefinitely from 
the soil without some restoration. If it is not furnished, the pro- 
duction evidently must finally be curtailed. 

The wonder, therefore, is not that apples should eventually need 
fertilization but rather that they can be grown for so long in some 
cases without it. Especially is this true when no one would think 
of attempting the same thing with many consecutive crops of wheat, — 
an actually less exhaustive crop. 

Part of the explanation of this is to be found in Table XXVII. 
Assuming for the present that most of the plant food of the leaves 
is returned to the soil, which may or may not be true, 1 as is the 
case with the straw, it will be noted that there is a marked difference 
between Ihe fruit and (he grain in the distribution of their demand 
for the various food elements. The demand of the apple is much more 
natural, i. e., it corresponds much more closely with the relative 
supply of these materials in the soil. The wheat grain, on the other 
hand, draws most heavily on nitrogen and phosphorus, which are 
relatively scarce in most soils. 

But even these elements are demanded sufficiently by the apple, 
especially when the wood ami leaves are also considered, to make 
them distinctly important items. It would therefore appear that in 
addition to the naturalness of the mineral demand, other factors 
must be operative in enabling trees to go for considerable periods 
without apparent need of outside fertilization. The most important 
of these is undoubtedly to be found in the long season of root activity 
in apples. 2 This naturally makes the mineral demand less acute dur- 
ing any given period, and thus enables the natural processes of 
solution going on in the soil to more nearly meet requirements at 
all times. The carbon dioxid, developed in the decay of humus or 
of green manuring 'covercrops, is also doubtless an Important aid in 
enabling these natural processes of solution to keep pace with de- 
mands. 

In apples, therefore, the naturalness of the demand, the return 
of most of the plant food used in the leaves, and the long season of 
root-activity with its accompanying reduction in urgency of demand 
at any given time, — all these influences combine in enabling trees to 
maintain themselves over considerable periods without need of extra 
fertilization. 



J As shown in the next section on mineral functions , much of the plant food of leaves is 
washed out, as maturity is approached and passed, and thus it may be returned to the soil 
to a considerable extent even if the leaves are blown away fairly soon after falling. 

2 As observed by Gorr (Wis. Rpts. I81S: 220-2-2S: and 1900: 291-294) and Cranefield (Wis. Rpt. 
1900: 306-8), the roots of apples and most other woody plants usually start growth in the 
spring before stem-growth begins, and continue their growth much later. Thus red currant 
roots on March .SI, 1898, were found to have made a new growth of as much as 3 inches, whi'e 
the buds were but little swollen: and in 1900. the roots of cherry, plum, pear and apple were 
found to be still growing on October 6, although no increase in twig-length had occurred 
later than July 1st, a difference of over three months. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 449 

Granting thai this may often be true for considerable periods, yet 
enough 1ms been presented above to show that apples really are by 
no means an inexhaustive crop, and that unless adequate returns are 
made, plant food in the long run should apparently inevitably become 
a limiting factor in any vigorous ami productive orchard. 

The Physiological Functions <ui<l Characteristic Effects of the Mineral 

A utrients. 

In the pages above, we have seen something of the amounts of 
mineral elements that are contained in the various parts of the apple 
plant. It remains to be shown approximately what are the generally 
accepted functions and characteristic effects in plants of the more 
important of these minerals and of nitrogen. This is desirable, as 
indicated earlier, partly as an aid in the diagnosis of any given case, 
and partly to assist in the accurate observation and interpretation of 
results in any given set of fertilization experiments, whether they 
be upon apples or wheat. 

At the outset, however, it must not be assumed that the exact 
functions of the various mineral elements are by any means fully 
known, either for plants or animals. Such knowledge is very diffi- 
cult to get. This is due primarily to the fact that owing to the inti- 
mate correlation existing between different functions, the common 
method of determining values 1 frequently disturbs or impedes the 
whole metabolic process, and thus often results in many changes 
that are not to be credited directly to the particular element omitted. 
The result is that in no case do we know the entire series of pro- 
cesses participated in by any element from the time of its absorption 
to its rejection by the plant. 

in plants, there are uniformly found some 15 chemical elements, 
but not all are essential. Those constantly found are the organic 
elements, — carbon, hydrogen, oxygen and nitrogen; — and the so- 
called minerals, — sulphur, phosphorus, potassium, magnesium, iron, 
chlorin, calcium, aluminum, sodium, manganese, and silicon. Of 
these, the last five have not been shown to be essential, although only 
the lower algae and fungi are known to be able to do without calcium. 
Hence, in the case of the higher plants, its value as a direct plant 
food seems to us as worthy of consideration as that of nitrogen or 
any of the other elements usually considered as physiologically active. 

Under normal agricultural conditions, however, the elements most 
likely to be lacking, or to be below their optimum, are nitrogen, phos- 
phorus, potassium, calcium and possibly magnesium. Our discussion 
is, therefore, confined to them and to iron, since the latter has been 
of some special interest to fruit growers. 

Nitrogen. — This element, with sulphur and phosphorus, served 
chiefly in the formation of protein and protoplasm. It occurs, there- 
fore, largely in the living areas, <•. g., the cambium layers, leaf meso- 
phyll and growing tips, or in seeds 2 and other food-storage organs. 
Like phosphorus, it migrates very strongly from the older, more 
mature, or dying tissues of plants to the living portions, and toward 
the heads or upper portions. Like potash and soda also, the assim- 



"J'his is by the absei or continued severe restrict ion of the particular element whose 

function is being studied! 
-Note Barth's findings In pits of stone fruits, under our Table XXI II. 

29—20—1910 



450 ANNUAL REPORT OF Off. Doc 

ilated nitrogen is apparently subject to very considerable losses as 
maturity is reached and passed, due to migration and the action 
of rain and dew. 1 

In general, the effect of nitrogen applications is to produce a strong 
vegetative growth, and to greatly retard maturity and ripening in 
most plants. Cabbage, which is merely a bud and hence a vegetative 
structure, constitutes an exception, it being hastened rather than 
retarded in maturity; and the same is apparently .rue, with early 
applications only, in the case of some other vegetables such as toma- 
toes. With apples the retarding effect is usually very marked. 

Where nitrate applications have been shown to increase the nitro- 
gen content of the crop, it has apparently been accomplished more 
by delaying maturity than by actual addition of N. This is brought 
out especially in the case of mangels, and also with wheat and barley, 
in the Eothamsted Experiments. These experiments also showed 
increased susceptibility to rusts and leaf spot in mangels, but in our 
own experiments with apples, in which the foliage had been attacked 
by the so-called "frog-eye" leaf spot (Sphaeropsis), these results 
were reversed, the nitrate-fertilized trees being much the more resis- 
tant. 2 

PhospJioius. — This element is an essential constituent of nucleo- 
proteins and renders their formation possible. It is therefore neces- 
sary for cell divisions and for all new growth, and in its absence these 
processes stop, as shown in Loew's experiments with algae. Its ab- 
sence also results in an accumulation of fats and albumin; and its 
presence is shown by Loew to be necessary for the formation of 
lecithin and chlorophyll. 3 

As might be expected on account of the demand for it in the new 
growth, there is an enormous migration from the older portions to 
the younger, and especially from the straw to the seeds of the grains 
and fruits during maturity. As with most other minerals, there may 
be considerable loss of assimilated P 2 5 , as a result of rains and dew, 
during maturity and the later stages of plant growth. 4 

An interesting side light appears in the fact that the protein con- 
tent of seeds and the yield of grain is said to be markedly increased 
by increased phosphorus supply. 5 

In the Eothamsted work, the ripening process was exceeedingly 
forwarded by phosphorus, giving a difference of 10 days in the case 
of the barley. It is, therefore, held to be a corrective for the retard- 
ing influence of nitrogen, and its effects are notably better in a wet 
season. This has not been clearly corroborated as yet in our apple 
experiments. 

In the English work also, P 2 5 was found to promote poot develop- 
ment very markedly, but not exactly in proportion to its supply, as 

1 See article of Le Clerc and Breazeale on "Plant Food Removed from Growing Plants by 
Rain or Dew." U. S. D. A., Year Book, 1908: pp. 389-102. 

2 See Penn. Sta. Bui. 91, figures 2 and 3: and Bui. 100: 25, 1910. 

3 U. S. Bureau of Plant Industry, Bui. 45: 16-19. Lecithin is a semi-soluble substance regularly 
accompanying fatty mattc~, but physiologically superior to it because of its partial solubility. 
It thus probably serves for respiration, being the form into which fat must be changed to 
become combustible in the protoplasm. 

4 In LeClere and Breazeale's work the losses with wheat were as follows: N, 7%; P^Ob. 33%: 
K2O, 54%: soda, 41%: lime, 34%; magnesia, 46%: and chlorin, 60%. In the work of Wilfartb, 
Romer and Wimmer, losses were found as follows: N, 23%; PsOr., 3%: K2O, 38%: and soda, 
47%. U. S. D. A. Year Book, 1908, pp. 395-97. 

C U. S. Bureau of Plant Industry. Bui. 45; 16-19. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 451 

there is an unknown factor cutting across results. Tillering and there- 
tor bud formation in stem and roots are greatly promoted by it. 1 

Potassium. — Some potassium salts are necessary for every living 
cell. They seem to be connected especially with starch formation. 
In their absence the polymerization of formaldehyde (C1I 2 0), the 
first organic compound in plants, into C 6 H 12 O a etc. apparently does 
not go on so readily. Potash also seems to be connected with protein 
formation, which may be a similar process, and with protein accumu- 
lations.- 'those parts in which carbohydrates arc transported are 
also reported to be relatively rich in potash/ though this does not 
prove any vital connection. 

Under normal conditions, potash is likely to be of special impor- 
tance as a fertilizer where carbohydrates are the important parts of 
the crop, e. g. sugar beets, mangels, and probably fruits. The latter 
point is indicated by the composition of apples as shown in Table 
XVIII, but it has not yet been clearly shown in our held experiments, 
probably because potash has not proved to be clearly deficient as yet 
on the check plots. 

In the Kothamsted experiments, when N and P are diminished, the 
yield of grain is reduced but the individual kernels are of normal 
size. When potash is lacking, however, the kernels are also under- 
size, thus indicating that assimilation has been checked in its ab- 
sence. Also there are many blind florets and weak seeds in wheat 
and barley ; and with grass there are many reddish or purplish leaves 
with dying tips on the potash-starved plots. In the English experi- 
ments, potash reduced rust-attacks on beets, and tended to reduce 
lodging in grain. It also appears to assist plants in resisting drought, 
as indicated in Atkinson's work on cotton leaf blight. 4 This is 
possibly due to its reputed value in increasing the osmotic power 
of the cell sap. 

There is a difference of opinion as to its relation to maturity, some 
maintaining that it hastens maturity and others that its usual effect 
is to prolong growth. Those holding the latter view consider it 
especially effective on the lighter soils and in dry seasons. The plant 
habit of closing up growth on the occurrence of malnutrition of any 
sort, probably accounts for some of the divergence in views. No 
marked effect either way has yet appeared in our apple experiments, 
though perhaps the tendency has been to hasten maturity. 

It is worthy of note tliat where citrate of soda has been used as a 
nitrogen carrier, in the Kothamsted work, no sign of potash failure 
has been observed in 12 years. This is taken to indicate that sodium 
liberates potash in the soil. 

While potash shows relatively little migratory tendencies in cereals 
at any rate, yet it is subject to very marked losses with increasing- 
maturity of the plants, as shown in the discussion of phosphorus 
above. 

Magnesium. — This element is required by all plants. Its distribu- 
tion and importance in them is apparently rather similar to potas- 



1 Lectures by A. D. Hall, Director of the Rothamsted Station in England, in 1908 at the 
Graduate School of Agriculture, Ithaca, N. Y. The other references here to Rothamsted work 
are based on these same lectures, 

2 This is indicated for example in the correlation of higher potash and higher protein con- 
tent in seeds of legumes as compared with those (if cereals. 

3 Loew. U. S. Bureau of Plant Industry l. r >: 28-30. 

♦Alabama Station Bulletin 36. Als sec Duggar's Plant Physiology, p. 174, 1911. 



452 ANNUAL REPORT OF Off. Doc 

shim. As pointed out by Loew, however, it can perform its proper 
function only in the presence of calcium salts, 1 since, with the excep- 
tion of a very few plants, it is strongly toxic otherwise. Loew con- 
siders it especially important in the formation of seeds and of pro- 
teins although it is required in the development of all plant parts. 

Its action is indirect, that is, it does not enter directly into the 
composition of plant parts or tissues, but apparently serves rather 
as a carrier of the phosphorus needed in their formation. Accord- 
ing to Loew, this view is probable because of the relatively easy 
decomposition of the secondary magnesium phosphate into territory 
and free phosphoric acid, a dissociation which would naturally im- 
mediately precede assimilation. At any rate, magnesia is found 
always to increase when rapid development is taking place, and com- 
paratively little of it will serve for extended physiological operations, 
which rather corroborates the view just stated. A connection between 
magnesia and phosphorus is also shown in the work of Heed on 
Spirogyra. 2 

As compared with lime, the magnesium content of leaves and wood 
is always noticeably lower, while the reverse is markedly true of the 
content of seeds, a and also of fruits as indicated for the apple in 
Table XVIII. 

Magnesium also migrates strongly to the growing parts, in general 
"following the proteids, like the phosphates." Its exact relation 
to fruit development is not known, though the results in the Massa- 
chusetts experiment 4 suggest a possible value. Its relatively high 
content in fruits, as well as its apparent relation to phosphatic com- 
pounds, is also suggestive. It seems that nothing is known concern- 
ing its relation to the hastening or retarding of maturity in crops. 

Calcium. — The use of lime in agricultural practice is very old. 
In many soils it is an important factor; and with the large demand, 
of most plants for it, its need is often felt very early. The part that 
it may play in the nutrition of plants is variable. In some soils, its 
action is physiological, while in others it merely modifies environment. 

Since fungi and certain algae do not require calcium, and since 
it may be largely or entirely absent from primary meristem and 
from young plant organs generally, it seems that lime is "not essential 
for vital activity in general but only for certain special processes." 5 
In the higher plants, however, it has apparently acquired such im- 
portance for these special functions, that its absence may indirectly 
affect one or all of the vital activities, and thus obstruct metabolism 
generally. 

The special function thai has been most clearly associated with 
calcium is concerned with the solution and transfer of starch, as 
contrasted with the starch-building role of potash. The irregularities 
in starch-transfer, in (he absence of lime-salts, were hist observed by 



iU. S. Bureau of Plant Industry. Bui. 45:55-67. 1903. 

2 Reed, H. S. The Value of Certain Nutritive Elements to the Plant Cell. Ann. of Bot. 
21: 501-543. 1907. 

3 U. S. Bureau of Plant Industry. Bui. 45. See pp. 35-37 on relative distribution of lime and 
magnesia in plants. The preponderance of Ca over Mg. in soils need not be especially great, 
though more appears to be required by crops having very abundant foliage. The experi- 
ments of May (1900) in Washington and of Aso and Furuta (1901) in Tokyo, indicate that 
cereals thrive best when the lime content of the soil only slightly exceeds that of magnesia, 
while cabbage needs twice as much lime, and buckwheat three time as much as magnesia. 

*See results in plots 4 and 5 of our Table XXXIV. 

5 Peffer. The Physiology of Plants, I: 433. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 453 

Boehm. In his observations, the starch accumulated in the ]>ith and 
Lower part of the stem and resulted in the death of the plants, the 
injury appearing first in the upper parts. The difficulty disappeared 
when lime salts were added. The function of lime in acid neutraliza- 
tion in plants is now considered less essential than formerly, since 
the resulting calcium oxalates are found to be absent in many plants. 
Boehm and Molisch also hold that lime is important in the laying 
down of the cell wall, particularly the middle lamella. 3 II' tine, ihis 
may have some application in fruit-production, since the mealiness of 
apples appears to be due to the breaking down of this lamella, with 
the consequent separation of the cells without rupture. The relation 
of lime-salts to this has apparently not been studied. 

In plants, lime accumulates especially in the leaves, as shown in 
Table XVII I, and to a less extent in the wood. Etiolated, diseased or 
albino leaves, contain much less lime than healthy green leaves, 2 the 
reduction sometimes being to less than half. And young pine trees 
grown in the absence of calcium produced new leaves only to half 
their normal size. 

It is therefore likely to be valuable in the fertilization of vegetative 
or leafy crops, such as cabbage, lettuce, and turnips. 

In its ecologic or soil-modifying capacity, lime may function as 
follows: (1) Corrects acidity. Most plants prefer slightly alkaline 
soils, though there are some important exceptions, which apparently 
include the cowpea, watermelon, grape, and Japan clover. The exact 
preference of the apple is not known. {'1) Liberates other nutrients'. 
This "whip" action lias sometimes been considered the only function 
of lime. The liberation should not become too fast, however, or 
losses may occur by leaching. (3) Tends to preserve nitrogen. (4) 
Flocculates heavy soils. (5) Possesses some fungicidal and insecti- 
cidal value. Thus it is often effective against snails, and reduces 
or prevents club-root of cabbage, but it favors potato scab. ((>) It 
corrects the toxic action of magnesium, and also of man// other bases, 
when they become present in injurious amounts. This function is 
discussed later, after the discussion of iron. 

Like magnesia, the relation of lime applications to maturity in 
planls is apparently not definitely known, as is also the case with 
their relation to the fertilization of orchard fruits. Our experiments 
thus far have been (dearly favorable in only half the cases, as indicated 
later. The total annual draft of lime i* evidently high, as shown 
in Tables XXVI and XXVII. lint \t-\y little of this is in the fruit, 
most of il being in the leaves. They doubtless return much of their 
lime content to Hie soil, even though soon blown away, owing to the 
large losses that occur on maturity, as shown in connection with our 
discussion of phosphorus above. 

Iron. Very little is known of the pari that iron plays in plant 
metabolism. It is required, however, in small amounts by all plants. 
It was formerly thought to be a constituent of chlorophyll, but this 
was shown by Molisch 8 not to be true. Its presence is still considered 
one of the indispensables for I he formation of chlorophyll, however, 
its action apparently being one of conditioning the nature of proto- 
plasmic activity. A small portion of the iron in plants also is appar- 
« . . — . — ~ 

'See U. S. Bureau oi Plant Industry, Bui. 45: 41. 1908. 

"See U. S. Bur. of Plant Industry. Bui. 45: 38-29.1908. 

■Molisch. Die Pilanzen in Ihren Beziehungen zmn Eisen, p. 81, 1892. 



454 ANNUAL REPORT OP Off. Doc 

ently held in the form of organic compounds, possibly entering into 
the strusture of the chloroplastids. 1 

As a fertilizer, Bracci 2 has reported that an application of one 
part FeS0 4 with twenty parts of cilt to wheat and oat soil, resulted in 
increased yields of straw and grain, and earlier ripening by several 
days. Ville 3 also reports that a spray of 2 per cent, solution of 
FeS0 4 upon young apples and pears both hastened the ripening and 
enlarged the fruits. To the writer this seems rather fanciful, though 
a serious attempt has been made to explain it on the ground of stimu- 
lation of the protoplasm and increased production of chloroplasts in 
the epidermis. 4 

Considerable discussion and some experimenting has been done 
among horticulturists on the value of iron applications to the soil 
in increasing color of fruit, especially of apples. This point is dis- 
cussed later, on pages 504-505, but it is sufficient to say here that 
the present evidence is not favorable. This may be because it has 
not been deficient in the soils tested. The amount of iron in the 
annual draft of apple trees is worthy of note, as shown in Tables 
XXVI and XXVTT. But it is probably always available in required 
amounts in any agricultural soil, so that additional applications 
could scarcely be expected to have any marked influence, at least 
not directly. 

The Toxic Action of Certain Bases and its Neutralization. 

In the discussion of calcium above, it will be observed that the sixth 
ecologic function given for lime is to correct the toxic action of mag- 
nesium, and also of other bases, when they become present in injurious 
amounts. This may frequently be a very important function of lime 
and it opens up a question that in our opinion has not received the 
attention it deserves in crop fertilization in general. 

This is the question of toxicity of the salts of various bases, es- 
pecially those of the heavy metals, when present alone in solution, 
or when distinctly predominating in solutions otherwise weak. This 
question is coupled with the related fact that their observed toxicity 
may often be reduced or entirely neutralized by the addition of other 
bases. 

This general relation was first discovered between magnesium and 
calcium by Loew about 1SS.°», but it has since been extended to salts 
of various bases or metals, such as sodium, potassium, strontium, 
barium, iron, manganese, nickel, cobalt, silver, mercury and the 
NH 4 -radieal in ammonium compounds. Their toxic action is shown 
to exist, above certain concentrations, often in very marked degree, 
and the neutralizing power of other bases, especially lime, is regu- 
larly shown to follow their addition. 5 The strong toxic action of 

1 Pfeffcr. Physiology of Plants. I: 426. 

2 Bot. Jahresber. p. 43. 1883. 

3 Bot. Jahresber. r>. 43. 1883. 

4 TJ. S. Bureau of Plant Industry, Bui. 45: p. 22. 1903. 

important references on this matter are as follows: Loew. Oscar. TJ. S. Bureau of Plant 
Tndustry, Bui. 45. 1903. Kearnev and Harter. Bureau of Plant Industry. Bui. 22. 1902. 
Kearney and Cameron, TT. S, Dept Agriculture Report 71. 190". Osterhout, W. J. TT. Bot. 
Gaz. 42: 127-134. 1906: 44: 259-272. 1907. Hansten. .Tahrb. f. Wiss. Bot. 47: 289-377. 1910. 

McCool, M. M., Thesis at Cornell University. 1911. 

Also see B-uggar's Plant Physiology. Chap. XVIII. 1911. (This boo\- has appeared since the 
abive discussion was written. Its Chapters VII and VIII also discuss mineral nutrients and 
their special roles.) 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



45E 



copper salts in solution also has long been known and utilized in 
spray materials and as an algicide. The neutralizing action of lime 
additions in these cases also is significant and may be similar to its 
action in nutrient solutions. 

The direct bearing of this upon certain results of our orchard ex- 
periments is given later, on pages 461 to 465. 



RESULTS FROM THE PENNSYLVANIA ORCHARD FERTILIZER 
EXPERIMENTS. 

A summary of the results on yield, color, size and growth for the sec- 
ond, third, and fourth years of our fertilizer experiments is given in 
Tables XXVIII to XXXI. Each of these tables gives the combined 
results from three experiments, the location and details of which 
are given in Table IV and its following discussion. From the latter 
table it will be observed that the first three experiments, — 215, 216 
and 220, — contain 480 trees ranging from 11 to 22 years of age; and 
the other three considered here, — 1336, 338 and 339, — contain 320 
trees in their fertilizer portions, ranging from 8 to 22 years of age. 1 
The total amount of fruit involved in the present tables, — XX VI 1 1 
and XXIX, — -is 222,568 pounds, or something over 4,450 bushels. 
This, in connection with the number of varieties and soil types in 
volved, makes the physical basis of these tables fairly satisfactory. 



Table XXVIII. 



■INFUENCE OF FERTILIZERS ON YIELD AND 
GROWTH IN APPLES. 



(Summary of Experiments, 215,216,220.) 



Plot. 



Treatment. 





$S 




© 


?°P 


d 


© 




~8 


8 


J2 


c. 


- x: 


© 








ai 














■o 


© 


-a 












£ 


'Z 


5! 


'E. 


r 9 




+? 






















'O 






3 


c 


3 


a 


iss 


H 


m 


(H 


pq 


' 



I, 

2, 

3, 

•1, 
5, 
6. 
7, 
8, 
9, 

10 

11 
L2, 
18, 

14 

15, 
16, 



cheek, ... 
N. P., ... 

N. K 

Check, ... 
P. K., ... 
P-K2SO4, 
Check, ... 
N. P. K., 

N., 

Check. ... 
Acid P.. . 
Raw P., . 
Check. ... 
Manure, . 

Lime, 

Check, ... 



76 
76.6 



83.4 
39.8 



71.9 

22.5 



—7.38 
—34.97 



23. 
—31.7 



0.024 
8,465 
6,318 
2,519 
5,177 
::,M'J 
2,650 
5,758 
:;,-i<k> 
4,574 
3,790 
2.896 
4,300 
2,618 
2,250 
3,221 



74.3 
71.35 



102. 

Hi.:.' 



75. 

—16.35 



-15.46 

-31.0, 



-33.55 
-37.17 



3.29— 

3.54 
3.63 
3.18 
3.34 

.:. 1:: 
::.-!» 
3.97 

(.(H 

3.48 

3.49— 

:;.:"> 

3.68 

4.30 

3.73 

3.26 



8.9 
19.1 



3.8 



18.2 

19.4 



—1.7 

—8.!) 



81.6 

9.6 



x The growth summary in Table XXIX also includes the data from the fertilizer portion of 
experiment 337, containing 180 trees, 3 years of age. 



456 



ANNUAL REPORT OF 



Off. Doc 



Table XXIX.— INFLUENCE OF FERTILIZERS ON YIELD AND 
GROWTH IN APPLES. 

(Summary of experiments, 336,338,339.) 















.£©• 


























o 






Sg 




























,Q 


g 


a> 


1 










" 


rt 


aj'G 


A 


Plot. 


Treatment. 




2 


© 


2 


a™ 


ft 
O 






















8 




rH 


s>> 


u 


60 














— M 








■a 


<H 


■c 


c 


siS - 


<n 








a 




a 


E Mfl . 


a 










N 












H 


« 


A 


<j 


a 



1,- 

2,- 
3,. 
4,. 
5,- 
6,- 
7,_ 
8,- 
9,_ 
10,- 



Check, .. 
N. P., .: 
N. K., .. 
Cheek. .. 
P. K., .. 
N. P. K. 
Check, .. 
Manure, 
Lime, ... 
Check, .. 



5,429 

11,607 
10,115 

7,841 

9,856 
13,018 

6,408 
10,551 
10,913 

9,107 



% 

83.3 
43.72 


33. 85 
S9.08 


126.5 
33.— 



3,780 
4,313 
3,000 
4,221 
5,207 
3,628 
2,905 
9,613 
5,453 
4,639 



% 
•9.82 
—26.36 



37.67 
8.52 



176.0— 
34.27 



2.82 
3.39 

(4.57— ) 2 
3.15 


% 

15.7 
(50.3)= 


3.04 
3.86 
3.59 


—7.9 
12.2 


4.25 
3.8 
2.98 


25.4 
19.5 







1. The growth summary here also includes the data from the trees "of the fertilizer portion of 
experiment 337. 

2. The growth increase shown on this plot appears so large that the showing is probably 
due to an inaccuracy somewhere, though we have been unable to find it thus far. 



Tabic AAA".— INFLUENCE OF FERTILIZERS ON AVERAGE 
SIZE AND COLOR OF FRUIT. 



(Summary from experiments, 215,216,220.) 


























































| 


00 

r-l 


o> 


O 
flb 







Plot. 


Treatment. 


■ 




V 












Jq 


0J 

'33 




,N 











0J 

Sao 


4^ 


so 




TJ 








C3 


« 


a 


<R 












































5 


> 




O 








■5) 


A 


<j 


A 


° 





1 

2 
3 
4 
5 
6 
7 
8 
9 

10, 
11 
12 
13. 
II 
15, 
16 



Check, 
N. P., 
N. K.. 
Check, 
P. K., 
P-K2SO4, 
Cheek, . 
N. P. K. 

N., 

Check, . 
Acid P., 
Raw P., 
Check, . 
Manure, 
Lime, .. 
Cheek, . 



oz. 

5.23 

5.28 

5.57 

5.57 

5.86 

5.52 

4.98 

5.62 

5.1 

5.98 

5.8 

5.65 

5.61 

5.93 

5.78 

5.86 



% 

—1.13 

2.22 


8.92 
6.56 


5.84 
—9.74 


— .86 
—1.39 


4.22 
.17 


. 



oz. 

5.54 

5.74 

6.206 

6.246 

6.24— 

6.03 

5.59— 

6.38— 

5.554 

6.264 

6.42 

5.95 

5.86 

6.88— 

6.004 

6.3ft 



3.5— 
7.4 



9.7 

-8.05 



4.72 

—.67 



14. 
—3.35 



% 

70.5 


% 


51. 1 
59.5 
75.2 
71.9 
68.7 
64.9 


—20.5 

—14.4 

.13 
.87 


45.8 

47.06 

68.8 


—20.37 

—20.39 


70.8 
75.1 
63.6 


3.8 

9.8 


56.8 
71.0 
71.4 


—9.4 
2.2 







No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



457 



Table XXXI.— INFLUENCE OF FERTILIZERS ON AVERAGE 
SIZE AND COLOR OF FRUIT. 

(Summary from Experiments, :::;<;, 338, 339.) 

















© 






















8 


O 


© 






s 






S 


1 


g 


Ci 


a 


rt 


Plot. 


Treatment. 


CM 




e 


- 


o 


o 






CO 


_N 


to 


N 


•«■ 


O 








jj 






•a 


49 






09 


<a 


a 


« 


S 


w 






t-t 


















a 




a 




a 








a> 














< 


pq 


<< 


M 


O 


m 



1 

2 
3 

4 
5 
6 

7 
8. 
9 

lit 



Check, 

N. P.. 
N. K., 
Cheek, 
P. K., 
N. P. K 
Check, 
Manure, 
Lime .. 
Check, 



oz. 
3.46 

3.55 
3.72 
3.31 
4.09 
3.58 
3.22 
4.58 
4.23 
3.25 


% 


oz. 
4.09 
4.19 
4.57 
4.11 
5.04 
4.30 
3.72 
5.53 
4.65 
3.82 


% 


% 
58.8 
37.9 

50.4 
53.4 
37.0 
53.2 
41.6 
52.8 
55.7 


4.10 
10.71 

24.7 
10.15 


2.27 

11.37 


26.6 
11.67 


41.8 
30.5 


47.0 
22.8 







-18.0 
-14.9 



2.1 

-15.2 



—12.4 
—2.1 



Methods of Obtaining Above Results. — The data <>n yield given in 
Tables XXVII] and XXIX were obtained by weighing and recording 
to each tree all the fruit produced in the three years indicated. The 
data on growth in the same tables were obtained by measuring all 
of the trees at the time of starting the experiments, and again three 
seasons later. The average increase per tree on the different plots 
is then found and used as the basis for determining the per cent, 
of benefit on the treated plots. 

The per rents, of benefit in all cases are determined by comparing 
the actual results secured on a treated plot with the "normal per- 
formance" of that plot. The "normals" for the plots are obtained 
by comparison with the two nearest checks. Thus if check plot I 
produced <I5 bushels of fruit and check plot IV produced 05, the 
normal production of plot II would be considered as 75 bushels 
and plot III as 85. In other words, the variation in productivity 
is assumed to be gradual between plots. These normals for the 
treated plots are then compared with the actual results obtained 
from them; and the per cent, of benefit for each treated plot is thus 
determined upon the basis of its own normal production. 

This method of normals is not without its shortcomings, some of 
which are indicated later; and it may in time be necessary to check 
it up at least, by the method of averages, the averages for the check 
plots being formed after excluding any that are evidently abnormal. 
For the present, however, the method of normals obviously fits our 
conditions better than any other that the writer is aware of. 

The data on color and average size, given in Tables XXX and 
XXXI, and in all other tables of our results, are obtained by the 
random sample method. It was manifestly unnecessary and im- 
possible, with the time and labor at our disposal, to count all the 
apples picked and to estimate ami record the amount of color on every 



458 ANNUAL REPORT OP Off. Docv 

fruit; and yet we desired approximately accurate comparisons. It 
was to meet that situation that the random sample method was em- 
ployed. 

In this method, a sample is taken at random from each basket of 
fruit as it is weighed ; this sample is placed with other similar samples, 
enough fruit being taken from each basket to make a total of one 
or two bushels in the total sample from each plot. The total sample 
is then weighed and the apples are sorted for color. This sorting 
is done on the basis of extent of color rather than intensity, because 
the former is much more sharply distinguishable; and, in general, 
within a variety in a single locality, the latter is usually closely cor- 
related with the former in any case. 

In the sorting, all fruits that are colored one-half or more are 
placed in one class, while those colored less than half are placed in 
the other. This process, of course, carries some color into the un- 
colored class, and vice versa; and it also requires steady judgment 
throughout a given experiment; but on the whole it has given very 
satisfactory results. The per cent, of fruits in the colored class is 
considered to represent the relative amount of color in the plot as 
a whole. From these percentages, the per cents, of benefit are obtained 
on the "normal" basis described above. 

The accuracy of this random sample method, of course, increases 
with the number of fruits in the sample. In most cases our numbers 
have seemed to be large enough, but as the yields increase it is prob- 
able that larger samples will be required. 

General Discussion of Results. — In the case of yield and size in 
the above tables, the results for 1910 are included to enable one to see 
the present trend and relative constancy in the effects of the various 
treatments. In general, in these and the following tables, the details 
of our results are sufficiently clear in the tables, so that our dis- 
cussion may be largely confined to the broader or less obvious phases, 
and to some of the principles apparently underlying the particular 
results obtained. 

In most cases, the elfects are seen to be fairly constant. In yield, 
in Table XXVIII, the marked exceptions are manure and nitrogen 
when used alone. In these a decided falling off in effect is noticeable 
* in the third year. There is also a marked increase in effect from the 
phosphate-potash combination in plot 5 of this table. This high 
showing of plot 5 is not fully maintained in Table XXIX, though it 
is steady and creditable there; and it may come up with increasing 
age as in XXVIII, in which the experiments are a year older. We 
suspect, however, that part of the extra high showing of plot 5 in 
XXVIII is due to the relatively poor showing thus far of its adjacent 
checks. 

Lime and raw phosphate or "floats" continue steady in their ap- 
parent injury to yield, in Table XXVIII ; while the former is simi- 
larly steadily beneficial in XXIX. Here again it would seem that 
the apparent injury of lime and floats in XXVIII is at least partly 
due to the unusually good yields obtained from checks 10 and 13, 
with which plots 12" and 15, — especially the former,— are compared. 
Any additional reasons for the poor showing that may exist are sub- 
jects for later study. 

In Table XXVIII, it will be observed that manure has fallen off 
badly on yield in the fourth year, while the plots receiving nitrogen 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 459 

in combination with other minerals are still showing strongly. It 
will also be observed, in Table XXIX, that these conditions are re- 
versed in 1910, which is the third year for the experiments recorded 
in it. From the evidence to date, we suspect that this is largely 
attributable to the quicker action of the nitrates as compared with 
the manure, which thus brings their full crops in about the second 
and fourth years, with corresponding relatively light crops in the 
third and Jifth years. The action of the manure on the other hand 
is likely to be about a year behind the nitrates in both respects. 

In support of this, and to show that the drop in efficiency of the 
nitrates in the experiments of Table XXIX is only temporary, we 
present herewith certain blossoming data of the current year, 1911. 
These data are from experiment 338, which is the oldest and most 
influential of the experiments in this group. The per cents, of full 
bloom on the various plots was as follows: 1 Plot I, 5 per cent.; 
II, 90 per cent.; Ill, 05 per cent.; IV, 2 per cent.; V, 25 per cent.; 
VI, 00 per cent. ; VII, 15 per cent. ; VIII, 75 per cent. ; IX, 12 per- 
cent. ; and X, 1 per cent. Inasmuch as plots I, IV, VII and X are 
checks and plots II, III, and VI are those receiving nitrates, it is 
evident that the prospects for the latter during the present year are 
exceptionally bright. 

Also the apparent drop in efficiency of nitrogen, that we do ob- 
serve, is doubtless connected in considerable part with the very dry 
conditions that have existed for the past three years in most of the 
localities where our experiments are situated. It is well known 
that lack of moisture is very often the limiter in many crops. This 
is especially true in some of our nitrogen plots, where the heavy 
foliage has proved a severe competitor with the fruit for such moisture 
as was available. 2 

The data on size, in Tables XXX and XXXI, are surprisingly con- 
stant with each table, as is seen by comparing the size-benefits in 
1910 with those in the three-season averages; but the extent of the 
benefit is much greater in the experiments of the latter table. All 
this is surprising to the writer, because, at the close of the second 
year of our experiments, attempts at correlating size with applica- 
tions of plant food had proved entirely fruitless; and we concluded 
at that time there was no definite connection between them. It 
still appears, however, that under certain conditions, indicated later, 
the size of the crop and the moisture supply are the dominant factors 
influencing the average size of fruit. 

It is also probable that the action shown for the various minerals 
in these tables, will still be found to be indirect and due rather to 
their relation to one or the other of the factors just named. For 
example, potash is shown here to have a distinct value in increasing 
the average size of apples. But attention has been called above, 
in our discussion of the function of potash as a mineral nutrient, 
to the fact that it increases the osmotic strength of the cell sap and 
thus enables plants to absorb water or resist drought better. Droughty 
conditions have been a marked factor in these experiments for the 
past three years, which would give this reputed property of potash 
an ideal opportunity to manifest itself. 

iThese observations wen* made on May 13, 1911, the date of full bloom, by Mr. J. B. Johnston, 
the ounor of the orchard. 
2 See Figure 12; see also Pennsylvania Bui. 100: 12. 



460 ANNUAL REPORT OF Off. Doc. 

The action of manure may also be due to its relation to moisture. 
Besides containing potash, it is well known that manure has some 
capacity to absorb and conserve moisture through its humus con- 
tent. But whatever the reason may be, its beneficial effect on size 
may evidently be very marked at times, as shown especially in 
Table XXXI, where the average size shows an increase of over 40 
per cent. The relation of lime to size of fruit shown, in the latter- 
table is rather anomalous, especially in view of its low content in 
fruit composition, and we do not attempt to account for it now. 
Its influence is practically nothing in Table XXX. 

Nitrogen, however, which is fairly high in fruits, appears to reduce 
rather than increase the average size of apples. It also constantly 
reduces color. Both influences are probably indirect, however, as 
will be brought out later. 

Values of the Individual Nutrients. — In the last four tables, we 
have seen the field effects that have followed the application of cer- 
tain combinations of mineral nutrients, although in some cases a 
nutrient has been applied singly. The results in those tables, taken 
directly from the trees, may be considered a close expression of the 
values thus far, of the various materials used, whether singly or in 
combination. 

In many cases, however, we may wish to know which is the more 
active element in a given combination, and approximately what values 
are to be assigned to each of the elements in it. Thus, in plot 2 of 
Table XXIX, we find a benefit of S3 per cent, resulting from an 
application of nitrogen and phosphate. Here the question arises as 
to how much of this effect is due to nitrogen and how much to phos- 
phate. Any answer to this can, of course, be only an approximation 
of the truth, hence the values obtained in the following table, XXXII, 
are not to be taken too literally. They are of interest, however, and 
are the closest answer to the question above that we are able to give 
at this time. 

In Table XXXII, the individual values, shown for the different 
materials when used in combination, are calculated from the data 
of the four preceding tables. Their values when used alone are se- 
cured directly from those tables. In particular, the values "in com- 
bination" are calculated from the per cents, of benefit obtained in 
plots 2, 3, and 5. The value of nitrates, 1 for example, is found by 
following the formula (NP-j-NK — PK) 7-2. In other words, the 
per cents, of benefit obtained in plots 2 and 3 are added, from this 
sum the per cent, of benefit in plot 5 is deducted, and the remainder 
is divided by 2. The quotient is considered to be the value of nitrates 
in the combination. The other values "in combination" are obtained 
similarly. 

Nitrogen is referred to here as nitrates to avoid confusion when considered "in combina- 
tion" and "alone." There is of course no evidence that green plants can use nitrogen in any 
other way than in some form of chemical combination. 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



461 



Table XXXII.— IN FUENCE OF FERTILIZER ELEMENTS ON 

YIELD, COLOR, SIZE AND (iRO WTH. 

(Estimated per cents, of Benefit.) 



Yield. 



(a) ExPta. 215,216,220. 



.Nitrates, 1 in combination, . 

Nitrates, alone ... 

Phosphates, in combination, 

Phosphates, alone, 

Potash, in combination, 

Manure, alone, 

Lime, alone, --. 



(b) Expts. 330,338,339. 



Nitrates, in combination, . 
Phosphates, in combination, 
Potash, in combination, ... 

.Manure, alone, 

Lime, alone, 



1908-10. 



34.6 % 

22.5 % 

41.4 
—7.4 

42.0 

23. 
-81.7 



1910. 



21.7 % 
—16.35 % 

52.5 
—15.4 

49.5 
— 33.. "> 
—37.2 



Color 
1908-10. 



—17.5 

—20.4 

—2.9 

3.8 

3.1 

- 9.4 

2.2 



46.6 

36.7 
—2.80 
126.5 

33.— 



—27.3 
36.9 

.7.". 
176. 
34.3 



—17.T) 

—.5 

2.6 

—12.4 

—2.1 



Size 
1908-10. 



Growth 
1907-10. 



3.92 


12.1 % 


9.74 


19.4 


2.79 


—3.2 


-.8(i 


—1.7 


6.13 


7.0 


4.22 


21.6 


.17 


9.6 



1908-10. 



—4.94 

9.04 

15.65 

41.8 

30.5 



30.95 
—21.25 
13.:::. 
25.4 
19.5 



]. The nitrogen, as already stated, was applied in the form of dried blood and nitrate of 
soda, ft is here called nitrates, however, to avoid misunderstanding. 

Since these results are derived from Tables XXVIII to XXXI, 
they are naturally not materially different. The exhibit is more 
compact, however, and the values of (he individual nutrients stand 
out more sharply. 

The data on color in the two sections of this table, lai and (b), 
are notably uniform, both qualitatively and quantitatively. The 
same is true qualitatively, and partially quantitatively, in all the 
other data here, except that on potash and lime in the yields of both 
columns, and that on nitrates and manure in the yield column of 
L910. An explanation for the lack of harmony in the latter case 
has already been offered above, in discussing the results of the pre- 
ceding tables. The disagreement for the single year is probably 
connected with the biennial bearing tendency, coupled with the year's 
difference in age of the two sets of experiments. 

The steady improvement with increasing age of the experiments in 
the effect of phosphates-in-combination upon yield, is one of the 
noteworthy features at the present time. When used alone, how- 
ever, phosphates have apparently decreased the yield. Also with 
each of the other materials, it will be observed that they are appearing 
distinctly more effective when used in combination than when used 
alone. 

The Occasional Harmful Effect of Potash and Other Fertilizers. 

Certain apparently discordant effects of fertilizers are compara- 
tively easily explained. Thus nitrogen, as shown above, is relatively 

steady in its improvement of yield and growth and its reduction of 
color .and average size of the fruit. These facts can be fairly readily 
accounted for. 



462 ANNUAL REPORT OP Off. Doc. 

But it is the occasional anomalous effects, — -those that appear one 
way in some cases and are reversed in others, such for example, as 
appear in the opposite effects of lime and of potash in the two sec- 
tions of Table XXXII, — these are the effects that are baffling and 
that incidentally may be most worthy of study in any search for 
new truth. 

Examining these lime and potash effects more closely, we see that 
they cross; that is, where one is beneficial the other is not, and vice 
versa. Thus in the experiments of section (a), potash gives an in- 
crease in yield of 42 per cent, for the three-year period and 40 per 
cent, in 1910, while lime in the neighboring plots is giving deficits 
of 31 per cent, and 37 per cent., respectively. In section (b), how- 
ever, while potash is showing a deficit or no beneficial effect, lime is 
giving 33 per cent, and 34 per cent, benefits. The full significance 
of this, we do not attempt to point out at this time ; neither can we 
guarantee the full continuance of the differences now observed. In- 
deed, we shall expect the potash deficit to disappear, for reasons 
indicated later, because of a heavy liming given to all the plots in 
Experiment 338, — the one in which the injury has been most ap- 
parent. 

But the fact that a number of mineral elements, and potash es- 
pecially, may have a harmful effect, — at least in certain forms or 
quantities, or in certain soils, — is not confined to this one observation. 

We have observed some forty cases of severe injury or death to 
young trees in two of our experimental orchards. In these cases 
the injury seems to be largely connected with muriate of potash ap- 
plications, though it is not entirely so. The general character of the 
injury as it appears on the twigs is shown in Figure 5. Under the 
title of "A New Disease on Apples," this disease was described in our 
last Annual Keport, 1 as follows: 

"A NEW DISEASE ON APPLES." 

"This disease is 'apparently physiological, and appears most conspicuously as an 
affection of the twigs of the current season's growth, though it is not confined to 
them. The twigs lose their normal color and become dull and of a rather blistered 
and mottled appearance at first. At a casual glance the effect somewhat resembles 
that produced by an incrustation of the San Jose scale. Immediately under the 
epidermis of the diseased areas and extending about half way to the cambium, in 
the early stages, there are numerous small, brown spots or pits where the tissues 
are dead or dying. Later, on the surface, the epidermis usually cracks around 
and over the diseased spots and they become rough, dark, and rather scab-like, 
and are usually slightly sunken through the drying out and death of the tissues 
underneath. In some cases the cracks may go deeper and involve the wood. The 
leaves are also affected sooner or later, probably through the girdling of the twigs 
below them. They turn brown, dry out and crumble, beginning at their tips and 
outer margins. In time, the twig, limb or whole tree may be killed. 

"The disease usually Incomes well developed and conspicuous by the middle or 
latter part of August. The appearance of the affected twigs taken on August 20 
is shown in figure 1." (Same as our present Figure 5.) 

"Specimens of the disease referred to our pathologist, Professor H. R. Fulton, 
were thought to closely resemble Sorauer's 'Tanbark' disease (Loh Krankheit). But 
specimens taken early in the following season and sent to Sorauer in Germany were 
pronounced by him not to be the disease referred to. The disease is. therefore, un- 
named as yet. This is the first record of its occurrence on apple trees in this 
country, so far as we have been able to learn, although there is evidence that it is 
similar in nature and origin to severe or fatal maladies which have been noted in 
other sta,tes on peaches and pineapples. Our present evidence points strongly toward 
its connection with heavy applications of a certain fertilizer.'' 

1 See Annual Report of the Dept. of Exptl. Horticulture, in Penn. Sta. Report for 1909-10. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 463 

Since writing the above description our attention has been called 
by our assistant, Mr. H. F. Hershey, to the possibility of iliis disease 
being identical with that described under the title of "Oedema of 
Apple Trees''* by professor George F. Atkinson, 1 in 1893. Specimens 
submitted to him, however, have 11ms far been pronounced not to be 
the same as the disease described by him. 

The disease, therefore, is still unnamed; but as this can be done 
better after the cause is known, we are continuing our search for 
the latter since it is the important matter anyhow. At present, 
the evidence still points to a connection between the disease and 
fertilizer applications, as will appear later, though potash is ap- 
parently not the only offender. 

Another observation that is very interesting in this connection 
is one made in experiments upon peaches by Professor L. C. Corbett 
in West Virginia, during 1899 to 1904. These results have not been 
published as yet, but notes giving the data were kindly loaned by 
him to the writer. In these experiments it was found that peach 
trees were readily killed with applications of 2-? f pounds per tree of 
muriate of potash, on old ground, while they were benefitted by 
similar applications, on new ground. With sulphate of potash similar 
results were obtained, but 5 pounds per tree were necessary to ac- 
complish this; 4 pounds being only sufficient to cause considerable 
injury. 

This difference in amount required to kill the trees is probably 
due merely to the marked difference in solubility of the two mate- 
rials, the muriate in water at normal temperatures being over three 
times as soluble as the sulphate. 2 This would doubtless result in 
a lower rate of absorption in the peach, as has already been shown 
to occur in the potato, 3 besides reducing the opportunity for toxic 
dominance in the soil solution, referred to below. 

These cases also show that the chlorine of the muriate is not the 
harmful agent, except perhaps in so far as it increases the solubility 
of the potash. The chlorine has been suspected, on account of cer- 
tain relatively injurious effects following the use of the muriate on 
apples in Masschusetts, 4 and also on account of similar effects from 
the muriate and the decided injuries from kainit in Florida upon 
pineapples. 5 

In these Florida experiments, also, they found that acid phosphate 
had an injurious effect on pineapples, which could be corrected by 
the use of lime. They attributed the injury to the sulphate of iron 
and aluminum which the acid phosphate contained, since P.,0 5 
derived from genuine bone black did not have any injurious effects. 
Nitrate of soda when used in sufficient quantity to furnish all the 
nitrogen required proved injurious both to plants and to the shipping 
qualties of the fruit. 5 Nitrogen from organic sources was beneficial, 
however. 

1 Cornell Bulletin 61: 299-302. 1893. 

8 At 20° O, the ratio of solubility in water of KC1 as compared with K2SO4 is 34:10. See 
Seidell. Solubilities of Tnorganlc and Organic Substances, pp. 241, 261; ion. 

»U. S. Bureau of Plant Industry, Bui. 45: 26. Observation is credited to Slollemd, In 
-Jour. f. Landwirtschaft.. Vol. 47: 305. 

■iTbese results are given later, In our Table XXXIV. 

BFlorida Station Report for year ending June 30, 1909, pp. 25-26: also see Florida Bulletins 
50, 83 and 101. 

33 



464 ANNUAL REPORT OF Off. Doc 

An Explanation of These Occasional Injuries. 

In looking back over this discordant and anomalous series of ef- 
fects, from the "crossed" results with lime and potash on yield; 
from the injuries to peach on old ground with materials that were 
beneficial on new ground ; to the injuries on pineapples from different 
applications involving certain kinds of carriers, injuries which were 
eliminated by the addition of lime or by changing the carrier to 
others not having a mineral base, — looking back over this series, 
there is but one comprehensive explanation that suggests itself. In 
the West Virginia work, we have shown that the injury can hardly 
be due to the chlorine, except possibly indirectly, therefore it would 
seem of necessity to be due to toxicity of the bases. This toxicity 
of certain bases, when alone or distinctly dominant in a solution 
otherwise weak, and also the related fact of its mutual counteraction 
by the presence or addition of certain other bases, are both well 
established physiologic facts, as we have shown above. 1 The only 
new thing here is their connection with certain conditions in the 
field which have hitherto been unexplained. 

Eeviewing our facts with this in mind, we see that the potash is 
harmful where the lime content is low ; hence lime applications there 
should prove beneficial, as they do. On the other hand, where potash 
is beneficial the lime content is probably already high, or at least 
sufficient; there, fuither additions of lime have apparently proved 
toxic. This is somewhat surprising, as lime in excess is not usually 
toxic. But it is not impossible, since cases of injury and death to 
young apple trees have been ascribed to lime-poisoning by Headdeu 
in Colorado. 2 The lime in our experiments is applied alone, at the 
rate of 1,000 pounds per acre annually, usually in the form of cal- 
cium oxid. 

Under this view also, the injury to peaches on the old ground is 
explained as due to the fact that the soil solution there was relatively 
weak,. thus permitting the potash to become unduly dominant, while 
in the new ground this did not occur. 

The injury to pineapples from acid phosphate applications, which 
were neutralized by the addition of lime, is what would normally 
be expected under our present view. And the value of the change 
in carrier of the nitrogen probably consisted in the elimination of 
the toxic influence of the sodium base. This, if our view is correct, 
might also have been accomplished by the addition of lime, unless 
the sodium accumulation should become too excessive, a condition 
which is relatively easy on the sandy soils of Florida. 

This basic toxicity view may also help to explain the observation 
above, that the value of each of the materials reported in Table 
XXXII was greater in combination than when used alone. Especially 
may this be true of some of the negative influences observable in the 
yields of 1910. But most of the single-year indications of injury 
are probably only apparent, and are really to be attributed to the 
biennial bearing tendency, as pointed out above. Moreover, the ac- 
tion of limiters and their removal is doubtless involved in the better 
showing of the materials when used in combination. 

In general, however, we see that our present hypothesis is very 
effective in accounting for the otherwise baffling series of observa- 
nce section on "Toxic Action of Certain Bages and its Neutralization," pages 451-455. 
*See Colorado Bulletin 131: 24-26. 1908. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 465 

tions recorded above. Its full proof, of course, will depend upon 
further analyses and experiments of a deductive character. These 
we can make in connection with our young apple trees especially, 
and it may be said in passing that thus far we have been unable to 
reproduce the disease on trees in another portion of our orchard, 
after it had been treated with two tons per acre of ground lime- 
stone. 

The Appearance and Financial (Jains in Certain Experiments. 

This phase of the subject was touched upon in our Bulletin 100, 
written in 1910. The discussion there is repeated here- with some 
slight modifications. 1 

"Some of these plots as they appeared in the field during the past 
season are shown in Figures G to 9. Figure 6 shows a portion of 
plots 13 and 14 of Experiment 220. The latter plot has received 
stable manure for three years, [now four years] while the former 
has received nothing. The yield of the past year was nearly 374 
bushels per acre on the manure plot and 28 bushels on the check. 
The variety here is York Imperial. 

"Figure 7 is a view of one of the check plots of Experiment 338. 
Checks 1 and 4 produced at the average rate of 150 bushels per acre 
during the past year; while plots 2 and 3, located between them, 
produced 721 bushels per acre. Every tree on the latter plots was 
loaded with fruit and required heavy thinning and propping, while 
neither was required on any tree in the former plots. The contrast 
in both foliage and fruit was vastly more striking in the orchard than 
it appears in the figures. Plot 2, which is shown in Figure 8, received 
nitrogen and phosphate while plot 3 received nitrogen and potash. 
In all other respects the latter plots were identical with the checks 
enclosing them. Figure 9 shows a view between plots 1 and 2. The 
variety in this case is Baldwin. 

1 Stewart, J. P. The Fertilization of Apple Orchards. Pennsylvania Station Bui. 100: 15-16, 
1910. 



30—20—1910 



466 



ANNUAL REPORT OF 



Off. Doc 



The results shown in Figures C to 9, together Avith some of our 
other most striking results, are considered further in Table XXXIII. 



Tabic XXXIII.- 



-FINANCIAL VALUE OF FERTILIZATION. 

(As given in our Bulletin 100.) 



Expt. 221, 1909 (3rd year). 





























03 


• 


.n 


















« 


ft 


^ 


<*H 




w 


03 


SH 










2 


3 


alue 


ost 


(H 


n 


>■ 


° ! 



Unfertilized, plots 4 and 7, 


19,448 
47,028 
48,550 


194.5 
470.0 
485.5 


$97.25 
235.00 
242.75 






Com. Fertilizer, plots 6 and 9 

Manure, plots 5 and 8, 


$13.00 
15.00 


$124.75 
130.50 


Expt. 220, 1909 (3rd year). 


Unfertilized plots 13 and 16, 


291 
1,94? 


27.9 
373.8 


$13.85 

$186.90 








$15.00 


$157. 9 j 






Expt. 338, 1909 (2nd year). 


Unfertilized, plots 1 and 4, 


2,607 
12,026 


156.4 
721.5 


$78.20 
360.75 


$15.00 




Com. fertilizer, plots 2 and 3 


$267.55 



"It is to be noted that the net gains are obtained after deducting 
both the cost of the fertilizer and the value of the unfertilized crop. 
Also the fruit here is valued at 50 cents per bushel, while the actual 
prices obtained for it varied from 50 cents to fl.25 per bushel, and 
any increase in the appraisement of the fruit of course will propor- 
tionately increase the net gain. It is also to be stated that in Experi- 
ment 338, especially, variations in the factors of tillage, spraying and 
pruning produced no material effect on the size of the crop, since the 
treatment of all plots in these respects was uniform, and tillage was 
varied in other portions of the experiment. 

"Such striking results as these of course are not to be expected 
everywhere. They evidently occurred here because plant food was 
the crop limiter in these orchards. For any given case this can only 
be determined by experiment. These orchards are on three diverse 
soil types. The soil in one case was evidently "run down ;" in an- 
other case it was in average condition; and in the third the soil 
condition was apparently above the average. These orchards are 
from 21 to 37 years of age and they are the only ones under experi- 
ment above 20 years old. Age, however, is not a sure index of the 
need of plant food, as one of our youngest orchards, a seven-year 
old, is responding strongly to fertilization, while some older ones 
have proved unresponsive. The big fact is that when such results 
as these are obtainable anywhere, it raises a strong suspicion that 
similar benefits may be obtained in many other orchards. And these 




e >? 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 467 

results .show beyond peradventure that in some orchards apple trees, 
like other plants, respond strongly and directly to application of 
plant food." 

Effect of Different Fertilization on Foliage. — "The beneficial effect 
of nitrogen on foliage is generally recognized. It is not so widely 
known, however, that this effect is often materially increased by 
the further addition of the other ingredients, phosphate and potash, 
and also that the latter constitutes in the absence of nitrogen appli- 
cations may exert a very marked influence. These facts are brought 
out in Figures 10 to 13, taken on October 20, 1909, and showing 
plots 4 to 9 of Experiment 220. All treatments have been in opera- 
tion for three years. 

•The effect of nitrogen on foliage appears much sooner than that 
of the phosphate-potash combination. The effect of the former ap- 
peared very distinctly within two months after the first application, 
which was made on July 8, 1907, 1 while with the latter materials 
the benefit scarcely became of importance until near the close of the 
third } r ear. 

"Besides the quick response to nitrogen which occurred here, 
other interesting results appeared. These trees in 1907 effectively 
resisted a severe drought and an attack of "frog-eye" leaf-spot, which 
early defoliated the untreated trees. They also came out into leaf 
much greener again the following spring and showed as marked 
differences in late May of 1908, before the second application, as 
they had shown in the proceding autumn. 2 " 

Relation of Fertilization to Fire Blight. 

This point has been under observation in our experiments for 
some years, and the existence of any relation has been questioned 
in some quarters. Up to the third or fourth year, and even yet in 
some experiments, there seemed to be little relation between fertili- 
zation, with its resulting differences in succulent growth, and fire- 
blight. In the later years, however, a marked relation has appeared 
in certain experiments. The manured plots and those in general 
that have been making the most vigorous growth are distinctly more 
affected with blight than those making less growth. Thus in Experi- 
ment 216 during the fourth year, the manured plot contained decid- 
edly more blight than all the remaining plots in the experiment. In 
Experiment 220 during the current year (the fifth), the only blight ob- 
served in the Baldwin section was on the manured plot. During this 
same year in Experiment 219, the blight was by far the worst on plots 
8 and 9, — those receiving mulch and manure, and mulch and complete 
fertilizer. These plots have uniformly been the most vigorous in 
this orchard. 

It is true that blight sometimes appears on trees that are receiving 
very poor treatment and are consequently making very poor growth. 
This is probably attributable to previous infections with consider- 
able canker formation, thus giving an abundant and immedate source 
of infection, or to special susceptibility on the part of the variety. 
Such cases, however, evidently do not prove that the character of 
the growth has nothing to do with blight injury, and our observa- 
tions above furnish direct evidence that the latter relation does exist. 

ift was applied in the form of nitrate of soda as a top-dressing. It was left uncultivated 
because of the fact that parts of the experiment are so rough and stony as to render tillage 
impossible. 

2 The above section is quoted from the writer's Pennsylvania Station Bulletin 100, p. 25. 



468 



ANNUAL REPORT OF 



Off. Doc 



Orchard Fertilization in Massachusetts. 

In the tables above, we have given data from extensive work during 
the relatively short period of four years. Its value consists chiefly 
in the duplications, the relative constancy of its results, and the 
large amounts of fruit and numbers of trees and soil types concerned. 
In the next table, we have data from the reverse conditions, — one 
experiment continued over 22 years. 

These data were kindly furnished to the writer by Director William 
P. Brooks, of the Massachusetts Experiment Station. The experi- 
ment has been running at the Massachusetts Station during the 
last 22 years. The trees were planted one year after the experiment 
was started and the plots contain three trees each of Baldwin, Bhode 
Island Greening, Boxbury and Gravenstein. The soil is a "moder- 
ately heavy, gravelly loam with a moderately compact (clay) sub- 
soil," and is stated to have been "highly exhausted, chiefly by the 
production of hay, before the experiment started." 



Table XXXIV.- 



FF UTILIZATION OF APPLES IN MASSA- 
CHUSETTS. 



(Treatment and Total Yields per Acre from 1889 to 1911.) 



Annual Treatment. 



S 



s 




£5 








a 




"O 


M 


o 
o 


1 

o 


n . 


eo 






o2 


o 


E 


s 



Ah 



a « * 

u Jo 

O ttfK 



Average girth, J 38 25 in. 

Ratios, --; 136.7 

Yields, lb, 26,203.5 

Ratios 574.4 

Color and size, 4 



33.23 in. 


27.98 in. 


32.27 in. 


118.8 


100. 


115.3 


14,500.5 


4,562. 


14,811 


319.1 


100. 


324.6 


1 


5 


3 



37.02 in. 

lSi.3 

22,245.5 

487'.6 



These results are similar to and corroborate those recorded in the 
preceding tables, Avith the differences in some cases even more dis- 
tinct. In every respect the treated plots have proved markedly super- 
ior to the untreated. The manure plot, which alone receives nitrogen 
in quantity, leads in yield and growth but falls next to the check 
in quality. It is closely followed in yield and growth and much 
surpassed in quality by plot 5, which received ground bone and low 
grade sulphate of potash. The superiority of 5 over 4 which differs 
only in the carrier of the potash is very interesting. The former 
has produced about 50 per cent, more fruit and over 15 per cent, 
more growth than the latter during the whole period of the experi- 
ment. There has been some question at the Massachusetts Station 
as to whether this is due to the magnesia in the low grade sulphate, 
or to a harmful effect of the chlorine accumulating from the muriate, 
or to a soil difference. 

A year ago we should have been inclined to credit it to the chlorine 
in the muriate, on account of certain constant superiority in our 
sulphate plots over the muriate, in the third year's results. In 




•1,V V tf • - , 



*F%$^S 






bi 


"O 


^J 


- 


* 




o 


an 


fc 


a 
o 




o 


t/J 


a 


► 


3 


,_, 


a 




03 


« 




-a 




»«M 



cd q 
o 

,a a 



fes.S 






«0 & 



~ 3 

be o 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 469 

Tables XXY11I to XXXI, however, it will be observed that ibis 
superiority has now vanished, and therefore we cannot charge the 
reduction and injury to the chlorine, except possibly indirectly, as 
indicated above, by rendering the potassium base more soluble. Ac- 
cording to our present basic toxicity view, the reduction in yield on 
plot 4 is due to an excess of potassium ions in solution; and if this 
is true, it should be capable of correction by proper applications 
of lime. 

Some Results from Tree Injections. 

Further results from manurial applications upon apple trees are 
given in connection with Experiments 217 to 221 (excepting 220). 
Before leaving the present discussion, however, which deals more 
directly with mineral nutrients in their relation to tree-feeding, 
it has seemed well to give some attention to the subject of tree 
injections, with special reference to their probable value and present 
results. Xothing of this sort has been done, as yet, in connection 
with our own experiments, but considerable experimental work has 
been done elsewhere. Very little of this work has been directed ex- 
actly at the question of fruitfulness, however, most of it being along 
the line of tree medication or rejuvenation, but the results observed 
are of interest in showing approximately what may be expected from 
such operations. 

The earliest work that has come to the writer's attention is that 
of a Russian, Mokrzhetski, reported in Russian periodicals in 1903 
and abstracted in the Experiment Station Record Vol. XVI, p. 932. 
Under the heading of a "New Method of Healing and Nourishing 
Trees," he described briefly his results from injecting various nutritive 
salts, both dry and in solution, into some five hundred trees. Tests 
were made upon oaks, poplars, frost-injured sycamores, diseased 
acacias, grapes, pears and apples. Iron sulphate is reported to have 
been successfully used against chlorosis, anthracnose of grape, and 
some fungus diseases of the apple. Solutions of acetic, oxalic, and 
tartaric acids were used against gummosis; and solutions of arsenic, 
copper sulphate, manganese, and barium are said to have been used 
more or less successfully in combating the bark bettle and a species 
of aphis. 

In France, Simon injected solutions of nitrate of potash, copper 
sulphate, purin, and sap-like solutions into the trunks of rather 
decrepit apples, peaches, vines and potatoes, with marked rejuvenat- 
ing effect in most cases. 1 

He was followed by Fron, working on pears and using solutions 
of iron sulphate and calcium nitrate. 2 Fron found that while the 
vigor of trees could usually be rather markedly increased, yet the 
improvement was mostly confined to a relatively small portion of 
the tree, and his net conclusion was that the method was of little 
practical value, though it might after several years serve as a guide 
for determining which elements should be added to the soil. 

In America the earliest work apparently is that of Bolley. 3 He 
used- many substances and concludes "that formaldehyde, copper 

J See The Gardener's Ohronicll (London), Third Ser., 41 (1907), No. 1045, p. 8. 
2 See Journal do la Societe National d'Horticulture de France (Paris), Fourth Ser., 10 (1909), 
pp. "'4-59. 
•See Reports of Xorth Dakota Station for 1904 and 1907. 



470 ANNUAL REPORT OS* Off. Doc. 

sulphate and iron sulphate, when properly applied, tend to hasten 
the recovery of apple trees from sunscald and sour heart, and to 
check the development of apple blight." The formaldehyde was 
used at strengths varying from one-half part to 2 parts per 1000 
of water, the rapid-absorbing trees requiring the weaker solutions. 
He reports increased vigor and fruiting in the treated trees, but 
states that care is demanded to avoid injury, and the resistance of 
trees to this injury was apparently extremely variable. 

Other work in this country has been done by Chandler at the 
Missouri Station, testing the effect of potash salts on the hardiness 
of peach trees ; and experiments on the value of injections in the con- 
trol of fire-blight, especially in nursery trees, are in progress by 
V. B. Stewart at the Cornell Station. In the last-named work, vari- 
ous fungicidal solutions have been readily taken up by the young trees 
through tubes attached to cut-off branches, but the result has usually 
been serious injury to the tree, even with solutions as dilute as 
one part of copper sulphate to 2000 parts of water. Similar serious 
injury to the young trees resulted from corrosive sublimate at 1 to 
500; lime-sulphur at 1 to 200; and a slight injury resulted from in- 
jections of potassium permanganate at 1 to 2000. Hence, little hope 
of success with injections of such inorganic materials is now en- 
tertained. 

The whole subject of tree-injections is thus seen to be in a rather 
unsettled state." The fact has been clearly established, that with a 
proper arrangement of tubes and receptacles, trees in foliage will 
readily take up considerable quantities of soluble salts. Nutritive 
salts or solutions in moderate amounts are frequently beneficial, 
though the effect seems to be more or less confined to one portion 
of the tree. Certain poisons, when used in extremely weak solutions, 
may be stimulative to trees, as they are to animals and other plants, 
and they may afford protection against certain diseases, though the 
evidence is not at all clear on this point, and their use must be at- 
tended with great caution. The problem is evidently one for the 
investigator, and one that requires much more study before anything 
definite can be offered to the practical orchardist. 1 

1 Part of the above section on tree-injection appeared in an article by the writer in the Rural 
New Yorker, 1911: 258. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 471 

BIBLIOGRAPHY: EXPERIMENTAL WORK ON APPLE TREE FER- 
TILIZERS, &c. 

The more important papers dealing with the results of fertilization 

and injection experiments upon apples and other fruits or allied 
plants are given below. We have made abstracts of these reports 
in nearly all cases, but space and time do not permit their inser- 
tion here. Some references have been included that have only a 
remote bearing upon apples directly, but they are entered because 
they contain some phase of the general subject of crop fertilization 
which seemed worthy of note in this connection. 



A. Tree Fertilization. Papers or Reports. 

1889. Wagner, Paul. On the Most Profitable Use of Commercial 
Manures. 
(Mass. Hatch Station. Special Bui. 3: 1-44.) 
Translation of a paper by. Paul Wagner, Director of the Agricul- 
tural Experiment Station at Darmstadt, Germany, on the General 
Status and Science of Manuring. 

1892. Bailey, L. IT. Fertilizers for Grape Cuttings. 
(New York [Cornell] Bui. J,!): 346-7). 

1S94. Dayton, Stephen C, Field Experiments with Fertilizers Upon 
Peach Trees. 
(N. J. Keport, 1894 : 121-127). 

1895. Yoorhees, S. S. Field Experiments w r ith Fertilizers Upon 
Peach Trees. 
(N. J. Keport, 1895: 107-110). 

1897. Colby, G. E. and Hilgard, E. Wl Effects of Fertilization on 
Citrus Fruits. 
(California Station Report, 1895-97, pp. 163-181). 

1897. Beach, S. A. Some Results of Wood Ashes in Apple Orchards. 

(New York [Geneva] Bui. U t 0: 681-90). 

1898. Schweitzer, P. Effect of Iron Sulfate on Apple Composition 

and Color. 
(Missouri Rpt. 1898: 82-83). 

1898. Bailey, L. H. Fertilizing an Apple Orchard. 

(New York (Cornell) Bui. 153: 122-26). 

1899. Rolfs, P. H. Pineapple Fertilizers. 

(Fla. Bui. 50: 1-104). 

1900. Maynard, S. T. Fertilizing Tests, etc. 

(Mass. Bui. 66: 1-19). 

1901. AVagner, A. Fertilizing Orchard Trees. 

(Weiner lllus. Gait. Ztg. 26 (1901) No. 10: 345-52). 

1901. . Experimental Fruit Culture at Wye College. 

(Gard. Chion., 3 ser., 29 (1901) No. 752: 332-3). 



472 ANNUAL REPORT OF Off. Doc 

1902. . Fertilizing Grapes with Nitrate of Soda. 

(Ber. K. Lehranst, Wein, Obst u. Gartenbau, Geisen- 
heirn, 1902: 15-16). 

1903. Hall, A. D. The Experimental Fruit Garden. 

(Jour. Southeast Agr. Col., Wye, (1903) No. 12: 48-9, 
pi. 1). 

1903. Smith, C. B. Experiment Station Work with Apples. 

(U. S. Office of Experiment Stations, Doc. 673: 537-570). 

1903. Card and Stene, A. E. The Effect of Fertilizers on the Color 
of Flowers. 
(R. I. Rpt. 1903: 199-229, Fig. 3). 

1903. Beaucaire. Suitable Fertilizers in the Cultivation of Lettuce. 

(Sci. Amer. Sup. 55 (1903) No. 1428: 22883. Trans, 
from Le Phosphate). 

1903-8. Munson, W. M. Experiments in Orchard Culture and Fer- 
tilization. 
(Maine Bulletins 89-122-139-155). 

1904. Bedford and Pickering. Results of Fertilizer Experiments 

with Strawberries, Gooseberries, Raspberries, Cur- 
rants and Apples at Woburn and at Milbrook. 
(Woburn Experimental Fruit Farm Fourth Rept. 1904: 
1-99). 

In a letter to the writer of April 6, 1911, Director Pickering states that no 
important change has occurred as yet on the plots chiefly reported upon here. But 
the "results in the lighter soil, which in 1904 (4th Report p. 84) were beginning 
to indicate that manures were going to have the expected action on apple trees, 
have become much accelerated and their action is very considerable. (See 5th Rpt. 
p. 53)." 

1904. Clausen. Results from Fertilizing Orchard Fruits. 

(Landw. Jahrb. 33 (1904) No. 6: 939-60, pi. 1). 

1904. Halsted, B. D. Report of the Horticulturist. 
(N. J. Station Rpt. 190 J t : 291-340, pi. 4). 

1904. Jenkins, E. H. Observations on Fertilization of Peach Or- 

chards. 
(Conn. State Sta. Rpt. 1904, part 5: 444-447). 

1905. Waugh, F. A. Fertilizing Apple Trees. 

(Country Gentleman, 71 (1905) No. 2762: 14). 

1905. Trenkner, B. Nitrate of Soda as a Fertilizer for Fruit Trees. 
(Gartenwelt, 9 (1905) No. 27: 313-16, fig. 4). 

1905. Voorhees, Jennie A. Fertilizers on Fruit. 

(N. J. Rpt. 1905: 295-334, pi. 1; also Halsted N. J. Rpt. 
1904: 291-340, pi. 4). 

1905. Knisely, A. L. Fertilizers on Prune Trees. 

(Oregon Sta. Rpt. 1905: 57-59). 

1906. Walker E. Suggestions on the Care of Apple Orchards. 

(Ark. Bui. 91: 141-210, fig. 18). 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 473 

1906. Miller, H. K. and Blair, A. W. Pineapple Culture III. Ferti- 
lizer Experiments. 
(Fla. Bnl. 88: 411-437). 

1906. Waters, H. J. Feeding the Orchard. 

(Mo. Sta. Cir. of Information No. 22: 1-32). 

1907. Hedrick, U. P. (April). Effect of Wood Ashes and Acid 

Phosphate on Yield and Color of Apples. 
(New York (Geneva) Sta. Bui. 289: 211-235). 

1907. Blake, M. A. Muriate and Sulphate as Sources of Potash 
for Strawberries; and Further Experiments with 
Apples. 
(N. J. Rpt. 1907: 132-133). An announcement of plans 
only. 

1907. Wheeler and Adams. Continued Test of Nine Phosphates 

With Different Plants. 
(E. I. Sta. Bui. US, March 1907). 

1908. Blake and Farley. Fertilizer Experiment on Apples. 

(N. J. Rpf. 1908). 

1908. Watts, F. Cacao Manurial Plots. 

(Proc. Agr. Soc. Trinidad and Tobago, 8 (1908) No. 2: 
53-71). 

1908. Brooks, Fulton and Gaskill. The Relative Value of Certain 

Sources of Nitrogen. 
(Mass. Rpt. 1908, part 2: 32-36). 

1909. Stewart, J. P. Orchard Fertilization. 

(Penn. Sta. Bui. 91: 3-19. 1909). 

1 909. Blake and Farley. Fertilizer Experiments with Cherries. 
(N. J. Rpt. 30: 95-96. 1909). 

1909. Blair, A. W. Pineapple Experiments. 

(Fla. An. Sta. Rpt. 1909: 25-26). 

1910. Muth, F. On the Use of Lime-Nitrogen in Vineyards. 

(Weinbau u. Weinhandel, 28 (1910) No. 13: 120). 

1910. Garcia, F. Onion Tests. 1905-1909. 
(N. Mex. Bui. 7//: 1-24, fig. 6). 

1910. Sannino and Tosatti. On the Effect of FeS0 4 Used as a Vine 
Fertilizer on the Yield and Quality of the Product. 
(Rivista (Conegliano), 4 ser., 16 (1910) No. 1: 2-5). 

1910. Sannino and Tosatti. Influence of Potassium Fertilizers on 
the Composition of Wine, Husks, and Lees. 
(Rivista (Conegliano) 4 ser., 16 (1910) No. 2: 25 29). 

1910. Stewart, J. P. The Fertilization of Apple Orchards. 
(Penna. Sta. Bui. 100: 3-28, fig. 10). 



474 ANNUAL REPORT OP Off. Doc 

1910. Blair, A. Wl and Wilson, E. N. Pineapple Culture VI. Fer- 
tilizer Experiments. 
(Fla. Sta. Bui. 101: 28-42). 

1910. Hall, A. D. Adaptation of Plant to Soil. 

(Jour. Eoyal Hort. Soc. XXXVI, July, Part 1: 1-21). 

An explanation of dominance of different plants in different fertilizer plots and 
on different soils as due to competition. Also indicates something of the character- 
istics and distribution of apple soils in England. 

B. Tree Injections. Papers or Reports. 

1896. Roth, C. A Method for Artificially Feeding Trees. 

(Chem. Ztg., 20 (1896), No. 35: 344-45. fig. 2). E. S. R. 
7: 962. 

1898. Mangin, L. Nutrition and Protection of the Vine by Injection. 
(Jour. Agr. Prat. 1S98, II, No. 52: 918-920). E. S. B. 

10: 758. 

1903. Mokrzhetski, S. New Method of Healing and Nourishing 
Trees. 
(Vyestnik Tavr. Zemstvo. 1903, No. 11, 12; abstract 
in Zhur. Opuitn. Agron., [Buss. Jour. Landw.] 
5 (1904) No. J,: 550-51). E. S. R. 16: 982. 

1903. Sheviryev, I. J. The Nutrition of Diseased Trees with the 

Object of Curing them and Destroying their Para- 
sites. 
(Sclsk. Khoz. i Lyesov., 1903; abs. in Zhur. Opuitn. 
Agron. Jour. Expt. Landw. 5 (1904), No. 1: 104-106, 
E. S. B. 16: 383. 

1904. Bolley, H. L. Tree Feeding and Tree Medication. 

(N. Dak. Bpt. 190 J f : 55-58). 

1907. Bolley, H. L. Tree Feeding and Medication. 
(N. Dak. Bpt. 1906: 35). 

1907. Simon, J. M. Hypodermic Injections in Plants. 

(Gard. Chron., 3 Ser., 41 (1907) No. 10^5: 8). E. B. S. 
18: 636. 

1909. Fron, G. Injections of Nutrients into Fruit Trees. 

(Jour. Soc. Nat. Hort. France, 4 ser., 10 1909 pp. 54-59, 
fig. 2). E. S. B. 20: 1035. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 475 

CULTURAL METHODS AS A FACTOR IN APPLE PRODUCTION. 

With apples as with other crops, probably the chief function of 
cultural methods is the proper control of soil moisture. Other 
associated functions, such as promoting- nitrification and killing 
weeds, are important, — sometimes more so than moisture control, — 
but the latter is usually the chief consideration. 

This is especially true of fruit trees. In them the moisture demand 
is large, both for use in transpiration and as a constituent of the 
fruit and vegetative parts. Hence a shortage in water-supply may 
occur very frequently in orchards, at least for limited periods during 
the season. In such cases, it may act very completely as the limiting 
factor and thus reduce or nullify the effect of all other operations 
in the orchard. Such an action has already been indicated as occur- 
ring in some of our fertilizer plots and it is quite probable that 
some of the failures elsewhere to get satisfactory returns from 
plant food applications have been due to a deficient moisture supply. 

it is true that some treatments with fertilizers, notably potash 
and apparently nitrogen to some extent, often have a tendency to 
reduce the evils of drought, at least so far as growth is concerned. 
This has been noted in our discussion of mineral nutrients, and 
also has appeared in some of our experiments. In general, however, 
we believe that a deficient moisture-supply is much more likely to 
reduce the efficiency of fertilization than the latter is to compensate 
for the former. 

Since the questions of moisture and plant food are thus so closely 
associated, our experiments upon cultural methods have been planned 
so as to give data not only upon the methods themselves but also 
upon these methods when used in connection with certain plant-food 
applications. 

The plans, treatments and other details of these experiments are 
given in Table IV, and in Figures 2 and 3 with their following dis- 
cussions. They include Experiments 217, 218, 219 and 221 ; parts 
of Experiments 336 to 339; and Experiment 331 in our experimental 
orchard at the college. Altogether they contain 1887 trees, 1419 of 
which are in partial or full bearing and include 11 varieties and 7 soil 
types. 

The results that follow are from 1403 trees, involving 9 varieties 
and 6 soil types, and cover either 3 or 4 years according to the experi- 
ment or phase concerned. The total amount of fruit, covered in the 
following data and produced during the periods considered, is 606,959 
pounds or somewhat over 12,139 bushels. The data from this fruit 
give us information on 12 different combinations of cultural methods 
and plant food applications, the combinations being indicated in 
Figure 2 and in the various tables that follow. The physical basis 
for these tables and conclusions therefore is somewhat larger in 
every way than that for our fertilization tables given above. 

The influence of cultural methods alone, — without any fertiliza- 
tion, — upon yield, color, size and growth is indicated in the following 
Tables, XXXV to XXXVII. 



476 



ANNUAL REPORT OF 



Off. Doc 



Table XXXV.— EFFECT OF CULTURAL METHODS ON YIELD, 
COLOR, SIZE AND GROWTH, WITHOUT FERTILIZATION. 















60 


>d 








es 


a 


A 






g 

*3 


S3 
O 


a 

o 




Expts, 217, 218, 219, Young Orchards. 


a 

83 


= O 


o 




O 




00 






rH 


> 


b- 






43 


4a 


43 




o 


o 8 


O 


o 




E 


S 


s 


fo 



Yield, 1910, I 8,610 lb 

Yield. 1907-10, j 23,658 lb 

Ratio, 1907-10, I 100 

Ratio, 1907-10, _ 

Ratio, 1907-10 I 




22,018 lb 

39,794 lb 

168.8 

141.2 

124.7 



18,011 lb 

31,891 lb 

134.8 

113.1 

100 



Color, % Apples colored I or more. 



Color, average % 1910, 
Color, average 1909-10, . 
Ratio, 1909-10, _„ 




85. 
85.3 
114.04 



Size, average weight of apples in ounces. 



Average weight, 1910, 4.35 

Average weight, 1908-10 4.45 

Ratio. 1908-10 _ 100, 

Ratio, 1908-10 _ __ 




4.22 

4.53 

101.8 



1907-9, Growth, increase in trunk girth, in inches. 



Average increase, 1907-09, 

Ratio, 

Ratio 




3.58 
100. 



No. 20. 



TUB PENNSYLVANIA STATE COLLEGE. 



477 



Table XXXYI.— EFFECT OF CULTURAL METHODS ON YIELD, 
COLOR, SIZE AND GROWTH, WITHOUT FERTILIZATION. 









a 

o 

B 
S 












u 

> 
o 






Expts. 


336, 338. 


Age S and 22 Yrs. 


•o 












Tillage an 


Sod mule 


Sod. 



Yield, 1910. ... 

\ield, 1908-10, 

Ratio, 1908-10, 

Ratio, 1908-10, 



18,407 lb 


32,119 lb 


142.7 


115.16 



17,937 lb 

27,889 lb 

123.9 

10O 



3,231 lb 

22,507 lb 

100 



Color. % Apples colored J or more. 



Color, average % 1909-10, 
Ratio, 



68.6 % 
100 



68.2 % 
116.2 



71.9 % 
122.6 



Size. Average weight of apples in ounces. 



Average weight, 
Average weight, 
Ratio, 1909-10, . 
Ratio, 1909-10, .. 



1910, . 
1909-10, 



5.46— 

4.51 
119.6 
115.0 



4.395 
3.92 

103.9 

100 


4.085 
3.77 
100. 







Growth. Average increase in trunk girth in inches. 



Average increase, 1908-10, 

Ratio 

Ratio, 




2.81 
100 



2.83 
100.71 
100 



478 



ANNUAL REPORT OP 



Off. Doc 



Table XXXVIL— EFFECT OF CULTURAL METHODS ON YIELD 
COLOR, SIZE AND GROWTH, WITHOUT FERTILIZATION. 



l.xpt. s>j>1. Mature orchards. 



'Yield, 1910, . 
'Yield, 11)07-10, 
Ratio, 




20,496 ft 

43,79) lb 

100 



Color. % apples colored J or more. 


Color, average % 1908-10, 


56.1 
100 


79.67 


Ratio, ^, 


142 


Size. Average weight of apples, in ounces. 


Average weight, 1908-10, 

Ratio 


4.81 
100 


5.33 
110.8 






Growth. Increase in trunk girth in inches. 






Average increase, 1907-09, 


2.9 
219.7 


1.32 


Ratio _ 


100 



The methods of obtaining the various kinds of data presented here 
are the same as those described above in connection with Tables 
XXVIII to XXXI, — the data on color and size being obtained by 
the random-sample method and that on yield and growth by weigh- 
ing the fruit and measuring the trunks of all the trees. 1 

In general, it will be observed in the above tables that there are 
rather marked differences between the various treatments, in nearly 
every case. In the case of color, these differences are constant in 
their direction throughout the three tables. They show that so far 
as color is concerned, sod or sod-mulch has constantly excelled tillage 
and cover crop by from 10 to 42 per cent. This influence is probably 
indirect, and it is to be considered as largely or wholly due to the 
hastening of maturity, as indicated later. 

In the other phases covered here, viz., yield, average size of fruit, 
and growth of tree, there is some crossing in the direction of the 
differences. For example in the mature orchard of Table XXXVII, 
the tillage and cover crop system has given double the growth and 
36 per cent, greater yield than the mulch system, while in the three 
young orchards of Table XXXV the latter system has given slightly 

1 The height and top-diameters of the trees were also measured, but for various reasons they 
were found to be less reliable indicators of growth than trunk-girth, and hence were not 
used In our calculations. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 479 

more growth and 41 per cent, greater yield than the former. The 
results from the two orchards of Table XXXVI in these and other 
respects are about intermediate between those of the other two tables, 
as will be observed. This is chiefly because the figures in this table 
are largely dominated by the greater yields of the older orchards. 

The differences observed in the yield and growth of Table XXXVII, 
as compared with XXXV, indicate that different results are to be 
expected from these methods in orchards of different degrees of ma- 
turity. In other words, the method of soil management that is best 
for a mature orchard may not be the best for one just coming into 
bearing, or one in which the bearing habit is not well established. 

The mulch system evidently appears at its best in the younger 
orchards. In them, with the herbage from between the rows and 
the three-ton-per-acre addition of straw, a very effective mulch of 
sufficient extent to cover the roots was maintained, while in the old 
orchard we were unable thus to cover more than probably half the 
roots. In the latter case, at least the outer half of the roots was under 
a typical sod and often in dust-dry condition. 

In the younger orchards, to which the treatments were applied 
after bearing age was reached, both the mulch and the sod treat- 
ments have undoubtedly exerted a hastening influence on bearing. 
The increased yields observed on these plots, as compared with those 
under tillage, are due primarily to more fruits per tree, since the 
average size of the fruit does not differ materially. This accelerating 
influence of sod may be seen further in our Table XXXIX, in the 
sod-and-manure plots especially. These plots, in both young and 
old orchards, are now leading all others in yield. This sod influence 
can easily be overdone, however, and made to disappear unless suf- 
ficient plant food and moisture is present. This is shown especially 
by the relatively low yields of the unfertilized sod plots of Tabh- 
XXXV, as compared with the corresponding mulched plots. 

The present evidence, therefore, is fairly clear to the effect that 
the relative value of the tillage and mulch methods may depend to 
a considerable extent on the age of the trees to which the methods 
are applied. 

There is also evidence that the character of the soil, especially 
with reference to its moisture relations, may exercise a very distinct 
influence upon the results of the two systems. In our opinion, these 
two facts will largely account for the conflicting results now being 
obtained in the two experiments of the Geneva Station, in the Auchter 
and Hitehings orchards; and also for the differences between the 
results given in Geneva Bulletin 314 and those of Ohio Bulletin 171. 

Going back to our own tables, XXXV to XXXVII, we see some 
interesting differences in effect on size. In the young orchards, 
besides increasing the yield by 41 per cent., the mulch method has 
increased the average size of the fruit by about 5i per cent., as com- 
pared with the covercrop method. With the mature orchard, the 
yield is much decreased, but the average size of the fruit is still 
greater, the figures for the mulch bein? — 30 per cent, and 10.8 per 
cent., respectively. In Table XXXVI, however, both yield and aver- 
age size are diminished by about 15 per cent, in each case. In the 
two experiments of this table therefore, it is evident that there were 
about the same number of fruits on the trees, and that the difference 

34 



480 ANNUAL REPORT OF Off. Doc 

in size is largely or entirely due to differences in moisture conserva- 
tion, with the advantage here in favor of tillage. 

In the young orchard of Table XXXV, however, where the mulch 
has been applied for four years instead of three, as in XXXVI, and 
where it covers the root systems more completely, the moisture con- 
servation has apparently been better with it than with the tillage- 
and-covercrop method. This is indicated by the larger fruit as well 
as larger crop on these plots. 

That this is entirely possible is shown by moisture determinations 
iD mulched and tilled soils made by Shutt, 1 at Ottawa, Canada, in 
1905 and 190G. The mulched soils were equal or superior to the others 
in every case. He also has found that leguminous plants, particularly 
hairy vetch, are much lighter in their moisture draft than grasses; 
and that the shade of growing vetch is a better moisture conserver 
than the mulch formed by cutting and leaving it in place. In other 
words, the loss by capillarity and evaporation from the practically 
bare ground was greater at Ottawa than the transpiration through 
the legume. 2 . 

An observation on our Experiment 333, during the current season 
(1911), confirms this opinion of hairy vetch, but indicates that there 
is a marked difference in moisture draft between different legumes. 
In plowing across the plots containing hairy vetch, alsike, crimson 
clover, mammoth and medium red clovers, the soil was found to be 
quite dry under the alsike, while it was moderately moist under the 
mammoth and medium red clovers and very moist under the hairy 
vetch and crimson clover. This was explainable under the crimson 
clover on the basis of its having gone to seed and checked its vegeta- 
tive activities. In the other cases, the wetness of the soil was closely 
correlated with the degree of pubescence or woolliness of the plants. 
The smooth and glabrous alsike thus proved to be an active transpirer 
of moisture, the moderately pubescent clovers gave off water less 
freely, and the relatively woolly vetch transpired least of all. 3 From 
these considerations, as a permanent cover in orchards, hairy vetch 
would be best and alsike least valuable of these legumes. 

In the case of our young trees above, it is probable that the size 
of crop per tree was never so great as to bring it into operation in 
decreasing the size of the fruit. In the mature orchard, however, the 
latter factor is probably operating. In this orchard also, the mulch 
has been applied for four years, but it is insufficient as yet to cover 
satisfactorily the whole root system, so that the conservation of 
moisture is undoubtedly best under tillage in this case, as shown 
by soil examinations. It would seem therefore, that, in producing 
the 30 per cent, increase of yield, the number of fruits per tree harl 
become great enough to react unfavorably upon the size of the in- 
dividual apples. This relation is discussed more fully later. 

The Effect of Adding Manures to the Different Cultural Methods. 
In the foregoing tables, we have seen that marked differences ap- 
pear between the various cultural methods when used alone, i. e., 
without any extra fertilization. The effect of applying such fertili- 
zation is shown below, in Table XXXVIII. 

a Report of the Chemist, Canada Experimental Farms, 1907, p. 151. 
2 Shutt, F. T. Report of the Chemist, Canada Experimental Farms, 1904, p. 158. 
3 See article by Wiegand, Karl M. The relation of hairy and cutinized coverings to trans- 
piration. Bot. Gazette 49: 430-444. June 1910. 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



481 



Tabic XXXVIII— INFLUENCE OF CULTURAL METHODS ON 
YIELD, WITH FERTILIZATION. 













a 












« 












01 
























O 












CO 


Expts. 


217, 


218, 


219. 


Young Orchards. 


Plots 2 ;md 
tillage. 




Yields, 1908-9 


23,747 lb 
17,243 


21,955 lb 

19,254 


23,774 11) 
27,740 


23,174 lb 


Yields, 1910, 


25,990 






Totals, 1908-10, 


40,990 
100 


41,209 
100.72 


. r >l,514 
125.7 


49,164 


Ratio 


119.8 






Kxpt. 221. Mature Orchard. 








Yields, 1907-09, . . 




41,181 tb 
9,283 


35,946 ft 
28,338 




Yields, 1910, 












Totals, 1907-10 




50,414 
100 


64,284 
127.5 




Ratio .. . 













As compared with the results in Table XXXV and XXXVII, those 
in the present table show very marked reductions and one reversal in 
the differences between methods. For example, differences in Table 
XXXV of 19, 68, and 84.8 per cent, are reduced here to 0.7, 25.7 and 
19.8 per cent., respectively. And in the mature orchard, a difference 
of 36 per cent, in favor of tillage and cover crops, with no extra 
fertilization, is converted into an advantage of 27.5 per cent, in 
favor of mulching Avhen fertilization is added. 

The reversal in the latter orchard may be largely accounted for 
by the practical absence of a crop in 1910 on the plots that received 
both tillage and fertilizers. This fact, coupled with a remarkable 
case of consecutive increase in yield, which has occurred on the 
adjacent fertilized and mulched plots, is directly responsible for the 
observed reversal of advantage between methods. The crop reduction 
in the former plots was to be expected on account of the very heavy 
yield the year before. But the steady annual improvement in the 
yields of the latter was very unusual and unexpected. 

The record made by these mulched trees, part of which also re- 
ceived manure and part commercial fertilizer, is as follows: In 1907, 
they produced 3,050 lb. of fruit; in 1908, 10,351 lb.; in 1909, 22,545 
lb. : and in 1910 they produced 28,338 lb. And this increase occurred 
on mature trees that were receiving no tillage. It is hardly possible 
for this series not to be broken in 1911. although we are informed that 
there is again a satisfactory amount of bloom on these trees. 

Just why the steady and increased bearing should occur on these 
plots, 8 and 9, while a decided biennial habit should develop on 

31—20 1910 



482 ANNUAL REPORT OF Off. Doc 

the adjacent ones, 5 and 6, which differ only in their cultural methods, 
we are unable to say as yet. As will be seen by the previous treat- 
ment 1 of this orchard, these trees were not unaccustomed to tillage, 
so that the unsteadiness of bearing in the tilled plots can not be, 
attributed to the strangeness of the treatment. It is possible that 
the undisturbed development of roots in the mulched plots, together 
with fair moisture conservation and abundance of plant food, may 
be the reason for their steadier bearing, but of this we have no 
positive proof as yet. 

Other cases of at least temporarily overcoming the biennial bear- 
ing tendency have occurred in our fertilizer experiments, especially 
in plot 8 of Experiment 220, and in some of the nitrogen and manure 
plots of Experiments 216 and 338. In plot 8 of Experiment 220, 
although it is rather unfavorably located, the trees have uniformly 
been so fully covered with fruit during the past three years as to 
require thinning, while the adjacent trees have not been even moder- 
ately covered during the period of our experiment. 

The leveling effect of fertilization, noted above, whereby it tends 
strongly to reduce or even reverse the differences normally associated 
with the various cultural methods, is partially shown in the follow- 
ing figures, 14 to 21. We say ''partially" because the differences in 
the greenness of the foliage and in the general health and vigor 
of the trees are not reproducible in the prints. The differences be- 
tween the fertilized plots and plots 1, 4, 7, and 10 which are unfer- 
tilized, are sufficiently great in most cases, however, to impress even 
the camera. 

These pictures were taken in Experiment 219, partly by the writer 
in September 1909, and partly by Mr. Hershey in June 1911. Distant 
views containing more than one plot in the same picture were taken 
wherever conditions permitted. This, of course, naturally reduced 
the differences in the pictures, but it gave better opportunity for 
comparison. 

In one case, that of plot IV, the failure to make satisfactory growth 
is not entirely chargeable to the method, which is tillage and cover- 
crop without fertilization. The soil in part of this plot is thinner 
than in the other portions of the experiment and the trees are having 
more difficulty in getting a good start without the fertilization, 
which has proved so effective in the other plots. 

We have stated above that our cultural method experiment gives 
data on twelve different combinations of crrltural methods and plant 
food applications. These combinations and their results on yield are 
given in Table XXXTX. _____ 

*See record of previous treatment in description of soils of experiment 221, following 
Tabic IV. 






goes. 




u 3ii 




plete 
over 
w Fi 






a w o 










> 


w fi 





9 a? » 

03 M-" 


a 


^S 




M 


SB" 


f^ 


9 ^ 




OS W Q 


hh" 


fl G> S 

a > «s 








.fi 5^3* 


en 


*J o*3 


O 






ft 






||.s 


■ih m 


CD 


^JJO 


> 


^.fi fi 


■*-> 


ju 0> 


e 


"" tA« 




T3-3^ 


s 


g > <u 




— -"-> O 






l> 


cd n 


^H 


~ cc 


hi 


zn u fi 




O «"H 


En 


ril,+J 




ft <x> c3 




NJ N 












0J.-I-H 




S-w- 1 




fi *~ ? ■ 




Sh CB OJrH 




o^^S 




-©2 






he tw 
merci 
with 
June, 








H 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 483 

Table XXXIX.— EFFECT OF MANURES ON YIELD. 

(When Used with Different Cultural Methods.) 

















< 


§ 
















h 


o 
















4) 




Expts. 


217, 


218, 


219. 


Young Orchards, 


1908-lfl. 


1 

9 

a 



Manure 12 T 


Com. fertilfz 
100 ft per 



Clean tillage. 

Tillage and cover crop, 

Sod mulch 

Sod, 



22,309 lb 
26,679 
37,730 
29,719 



33,560 ft 
33,169 
45,727 
51,532 



40,256 ft 
40,493 
45,309 
34,995 



Totals, 1908-10 116,437 

Ratio - 100 

Ratio, i 



163,988 
140.8 
101.8 



161,053 
138. 
100 



Expt. 221. Mature Orchard. 1907-10. 



Tillage and cover crop, 
Sod mulch, 



Totals, 1907-10, 

Ratio 

Ratio, 




49,600 ft , 47,826 ft 
65,894 58,496 



115,494 
113.4 
108.6 



106,322 
104.4 
100 



In general, it will be observed that in every case but one the yields 
from the fertilized plots have surpassed those from the unfertilized. 
This one exception is the tilled plot 4 of Experiment 221. The full 
year for this plot was in 1910, the year in which as stated above, the 
corresponding tilled-and-fertilized plots of this experiment had prac- 
tically no fruit. This largely accounts for the present superiority 
in the total yields of the unfertilized plot 4. 

The trees of this plot also are naturally the best in the orchard, 
and are said to have yielded considerably better than the others be- 
fore our experiment started. Being close to the house they have 
doubtless received somewhat more fertilization and other care than 
the others farther away. And the present system of tillage, with 
the heavy green manuring that is being furnished by the cover crops, 
is apparently all that is needed to give good yields. It will be ob- 
served, however, that even this plot is now being surpassed by the 
mulch and manure plot of this experiment. 

In total effects, fertilization shows a gain in every case over its 
absence. In the young orchards this gain is from 38 to 40 per cent. 
In the mature orchard, the gains are now smaller, owing chiefly 
to the biennial bearing that has developed in the tilled plots, as in- 
dicated above. The full crop of the past year was on the unfertilized 
plot with very light crops on those receiving fertilization, and an- 
other year's crop is required to give both plots the same number of 
full and off years, since the habit became apparent. 



484 ANNUAL REPORT OF Off. Doc 

In the relative effect of manure and the commercial fertilizer used 
in these experiments, there is not much difference. The total super- 
iority of the manure runs from about 2 to 8| per cent., although, as 
stated in our treatment description, much more actual plant food 
is being applied in it and at a greater cost. It should be remembered 
however, that the fertilizer used here is a "complete" one, i. e., it 
carries nitrogen as well as the mineral elements. In many discus- 
sions of commercial fertilizers in their relation to fruits, the term 
has apparently been restricted to the mineral elements only. Also 
in a number of experiments, the nitrogen element has been omitted 
entirely, a fact which doubtless has had much to do with the lack 
of results. 

In connection with the different cultural methods, it will be ob- 
served that the plots receiving manure in combination with sod or 
sod-mulch are now leading all others in both divisions of Table 
XXXIX. Also manure in conjunction with tillage is now slightly 
in the lead in the mature orchard. This condition is reversed, how- 
ever, in the younger orchards, by about 20 per cent, in both tillage 
methods. It is hot yet clear whether or not this fact has any real 
significance. At any rate, the data show that either material may 
be used satisfactorily with either cultural method, when the orchards 
are not being limited by other conditions. 

Influence of Manures Upon Other Crop Phases.— The influence of 
the above manurial applications upon color, average size of fruit, and 
tree growth is shown in Table XL. 



No. 20. 



TUl-: PENNSYLVANIA STATE COLLECT. 



485 



Table XL.— EFFECT OF MANURES ON COLOR, SIZE AND 

GROWTH. 



A. Expts., 217, 218, 219. (a) Color. % Apples colored J or more. 



Coior, average % 1908 10, 

% benefit, _. ..- 

Ratio, 



73.5 



63.1 

—10.36 

85.85 



64.7 
—8.8 
88.03 



(b) Size, Average weight of apples in ounces. 



Average weight, 1908-10, 
Ratio, 



4.19 
300 



(e) Growth. Increase in trunk girth, in inches. 



4.53 
108.1 



4.52 
107.9 



Average increase, 1907-09. 

Ratio, _. _-. 

Ratio, 



4.12 
100 




4.43 
107.5 

103 



B. Expt. 221. (a) Color. % apples colored h or more. 



Color, average % 1908-10, 

% benefit, 

Ratio 



(b) Size. Average weight of apples in ounces. 



65.5 
-2.4 
96.47 



66.2 
—1.7 

97.5 



Average weight, 1908-10, 
Ratio 



5.07 
100 



(c) Growth. Average increase in trunk girth in inches. 



Average increase, 1907-09, 

Ratio _ 

Ratio, 



4.22 
100 



5.65 
111.4 




5.42 
106.9 



4.92 
116.6 
100 



As shown in this table, the effect of manures on the phases con- 
sidered has been fairly distinct in both old and young orchards. 
Their usual effect of reducing color is apparent here, just as it was 
in our fertilization experiments above. The reduction in this case 
is less with the commercial fertilizer, doubtless on account of its 
smaller nitrogen content, thus causing relatively less delay in ma- 
turity. 



486 ANNUAL REPORT OP Off. Doe 

There lias been some increase in size of apples and in wood-growth 
following the fertilization. The increase is somewhat greater with the 
manure, in all cases, except that of growth in the young orchards, 
where the fertilizer has shown slight superiority. This may be con- 
nected with the smaller area over which it is distributed, thus giving 
relatively stronger applications; but the difference is hardly great 
enough to warrant definite consideration. 

The increase in size of fruit is probably again rendered possible 
here, because the accompanying increase in yield has not been great 
enough to bring in the reducing influence of extra crop size. In 
support of this view it may be noted that the increase in size is 
somewhat greater on the mature orchard, where the accompanying 
increase in yield has been less. 

Some General Remarks on Certain Methods. — From what has been 
seen above, it is evident that there is no one best cultural method 
for all situations. It is doubtless true that for the mature orchard, 
where the tillage-and-covercrop method is available, it is generally 
to be preferred, using tillage at least as often as every other year. 
The same statement probably holds for the young orchard until bear- 
ing age is approached. This is apparently true so far as the in- 
fluence of the inetbod itself is concerned. 

When used in conjunction with fertilization, the evidence at pres- 
ent is not so clear. This is because of the remarkable and regular 
increase in bearing that has taken place in the mulched and fertilized 
plots of Experiment 221. If this continues, it will indicate that the 
yearly root pruning occasioned by tillage is of more consequence 
than has been supposed. For various reasons, we are beginning to 
look with less favor upon the heavy pruning of tree tops, 1 and it is 
quite possible that something of the same attitude will develop in 
connection with root pruning, such as occurs in the ordinary methods 
of tillage. 

Where tillage is impracticable, however, as is the case in many 
good orchard locations, and sometimes where it is available, the 
mulch method may often have much to commend it, as indicated in 
our results. Without attempting to champion it or any other single 
method, we may sum up the situation in regard to proper mulching 
as follows. It avoids erosion on sloping ground; reduces labor; 
avoids the root-injury due to cultivation; increases color; enhances 
the value of the fallen fruit; apparently hastens bearing in young 
trees; may assist in blight control; and effectively conserves moisture, 
if the mulch is maintained sufficiently deep, which means three or 
four inches at least. Its defects are: frequent high cost of sufficient 
materials for effective mulch ; probable reduction in yields in mature 
orchards, unless accompanied by sufficient and proper fertilization; 
possible danger from mice and from fire; favorable hibernating 
quarters for injurious insects and fungi ; and lack of flexibility in 
moisture control, the moisture being conserved as thoroughly in 
late fall, when not often wanted, as it is at any other time. Its 
successful use, therefore, is likely to depend on age of trees, local 
conditions, prevailing pests, relative cost of labor and of mulch 
materials and the general moisture conditions of the orchard in 
which it is used. 

iSee Report of Woburn Experimental Fruit Farm lor 1907, for example. In this report it 
is shown that all pruning, regardless of season, tends to delay fruiting and reduces both yield 
and growth, the reduction being approximately in proportion to the severity of the pruning. 



t ►r-3 a> 
a> £p to 

IT) Cm en 

[0 (D g hjj 

iZ P - • Cfl 

Rffp H 

r-f a <D 

2-~d£ 

<-»- p O ^ 



eo 



B en 2 
_.« & O 

^£3£ 2 
pro ST 13 ' cc 

n B"<2 (i i-h 
p rt> O p - 

p'2 P l_l 

•o p S.^ ^ 

<^5 | -* |_| G 

<t> «> — 1» ° 

"S B >-• 

"1 T3 



=p 



<t> CD 



•e b" — P 

<t> CD B,' <tj 

p N — 

B d"' in: 

O B*i— 1 





> 

0)hS O 
cc t— i d) to 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



487 



Distribution of Feeding Roots in Apple Trees. 

This is a question that is of interest both in the application of fer- 
tilizers and the use of cultural methods. It has received some atten- 
tion in various places, of which we may cite the Experiment Stations 
in Wisconsin, 1 Illinois, 2 Arizona, 3 and Ohio, 4 and the Woburn Ex- 
perimental Fruit Farm in England. 

The greatest depths of roots observed at the various places are 
as follows: Wisconsin, 9 feet; Illinois. 5 feet; and Arizona, 20 feet, 
in the case of an irrigated peach root. In Ohio, the roots apparently 
were examined only to a depth of one foot, but it is stilted that in 
all cases studied most of the feeding roofs were removed in the first 
six inches of soil. 

In order to get more evidence on this question, especially with 
reference to the particular conditions existing in our own experi- 
ments, in 1908 we made some studies of the root distribution, both 
horizontal and vertical, in each of 28 apple trees. The results are 
shown in the following Table XLI. 



Table XLI.— ROOT DISTRIBUTION IN APPLE TREES. 

(As observed in the Pennsylvania Apple Experiments in 1908.) 



Vertical Range of Feeding Roots. 



Expt. 



Variety. 



Root Length 
Age in 1908. Ft. 



Range of depth Zone of Maxi- 
Observed. In. mum Numbers, 
la. 



216, 
216. 
217, 
217, 
217, 
217, 
218, 
218, 
218, 
218, 
213, 
219, 
219, 
219, 
220, 
220, 
221, 
221, 
221, 
221. 
336, 
336, 
336. 
338. 
338, 
338, 
339, 
339, 



Jonathan 

York Imper., „ 

York 

Gano, 

York, 

Gano, 

Albemarle 

York, 

Albemarle, 

York 

Jonathan 

York, 

Jonathan, 

York, 

Baldwin. 

York, 

Baldwin 

Baldwin, 
Northern 
Northern 
Grimes, . 
Smokehouse, 
Stayman, . 
Baldwin, ... 
Baldwin, ... 
Baldwin, .. 
Baldwin, ... 
Fallawater, 



Spy, 
Spy, 



Averages,— (28 trees). 



13.5 

11. 

10.75 

18.75 

16 

12.5 

18 

10.2 

5.75 
15.25 
10.5 
11.25 
11 

9.75 
27 

19.75 
39 
30 
36.5 
45.5 
14 

13.5 
14.5 
21.5 
27.75 
3B.5 
28.25 
25.75 



1 to 12 
1 to 12 
1 to 25 
1 to 2o 
1 to 18 
to 24 
to 33 
to 26 
to 24 
to 10 
to 20 
1 to 19 
1 to 19 
1 to 20 
1 to 18 

1 to 24 

2 to 24 
1 to 22 
1 to 20 
1 to 36 

1 to 32 

2 to 15 
1 to 18 

I to 42 

to 20 

II tO "' 

1.5 to 18 

1 to 23 



19.77 



1.07 to 22.16 



2 to 7 
1.6 to 7 
2 to 17 
2 to 8 
2 to 10 

2 to 16 

1 to 21 

4 to 15 

3 to 15 

5 to 12 

2 to 10 

2 to 11 

3 to 13 

5 to 15 

6 to 14 

1 to 8 
6 to 14 

4 to 15 

3 to 12 

4 to 14 

2 to 11 

3 to 10 
2 to 9 

2 to 12 

3 to 10 
.5 to 10 

2 to 11 
2 to 11 



2.7 to 12.0 



^off, E. S. A Study of the Roots of Perennial Plants. Wis. Rpt. 1897. pp. 
2 Burrill and Blair. Effect of Cultivation on Root Systems. 111. Bui. 52: 109-10, 1898. 
3 McClatehie, A. J. Arizona Station Rpt. 1899. pp. 257-59. 
4 Green and Ballon. Ohio Bulletin 171. 



488 ANNUAL REPORT OP Off. Doc. 

The general character of the soil in each of these experiments is 
stated in Table IV and its following discussion. Since the study was 
rather of a preliminary nature, relatively simple methods were used, 
as follows. 

In getting at the root length, trenches were started, about in the 
center of the square formed by four trees, and continued until a 
root of some size was found. This root was then followed until its 
tip was approximately reached, and the total distance from the 
parent tree was determined. This of course did not always locate 
the really longest roots, but it gave information upon the roots that 
were among the longest of those originating from the four trees 
forming the square. 

In determining the vertical distribution, trenches were dug at right 
angles to a line of emergence of the roots and about midway between 
the trunk and the tips of the branches. These trenches showed the 
depths of the roots coming from that side of the tree, and they were 
continued downwards until further appearance of roots apparently 
ceased. 

From the results in Table XLI, it will be seen that the maximum 
root-length observed was 45£ feet. This was in a Northern Spy 
tree of Experiment 221. The maximum deprh observed was 42 inches 
in a Baldwin of Experiment 338. The general depth of maximum 
numbers of feeding roots ranged from 2.7 inches to 12 inches, on the 
average, with extremes of to 21 inches. 

It will thus be seen that the root-feeding zone is relatively shallow 
in apple trees, at least under many eastern conditions, where the 
soil moisture is usually fairly abundant until the surface is nearly 
reached. In more arid conditions, such as are found in Arizona, 
however, the roots may go downward to very considerable depths. 
The direction of growth in apple roots is therefore evidently governed 
largely by moisture supply, as is the case with other plants. 

Hence the cultural method that conserves moisture best will prob- 
ably tend to reduce the depth of roots, rather than increase it, so 
far as the direct influence of the method itself is concerned. The 
danger of excessive root-pruning by plowing deeper than 4 or 5 
inches over apple roots, under normal conditions, is also very appar- 
ent. In some cases the trees seem able to stand it, but we believe 
that there is opportunity for caution and improvement in this regard. 

BIBLIOGRAPHY TO CULTURAL METHODS AND ALLIED SUBJECTS. 

The more important papers and reports dealing with experiments 
upon this subject that have come to our attention are as follows. 

A. Cultural Methods. 

1893. Bailey, L. H. Does Mulching Betard the Maturity of Fruits? 

(N. Y. [Cornell] 59: 243-54, Fig. 1). 

1894. Bailey, L. H. Cultivation of Orchards. 

(N. Y. Cornell Bui 72: 297-314, 1894). 

1896. Craig, J. Mulching to Retard Blossoming of Large and Small 
Fruits. 
(Canada Experimental Farms Rpt. 1896: 158-60, Fig. 2). 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 489 

1807. Voorhees, JO. B. Apple Growing in New Jersev. 
(N. J. Bulletin 119: 1-23). 

1898. Bun-ill and Blair. Effecl of Cultivation on Root- Systems. 
(Illinois Bui. 52: 109-10). 

1898. Burrill and Blair. Cultural Methods for Orchards. 
(Illinois Bui. 52: 105-12, pis. 13). 

1898. Bailey, L. 11. Why are Orchards Barren? 
(N. Y. Cornell Bui. 153: 126-27). 

1900. Goethe, R. and Junge, E. Methods of Apple Cultivation on 
Light, Porous Soil. 
(Ber. K. Lehranst. Wein, Obst u. Gartenbau, Geisen 
heim, 1899-00: 13-15). 

1900. Whitten, J. C. The Apple Orchard. 

(Mo. Bui. J,9: 1-21). 

1901. . Apple Growing on Grassy Hillsides. Hitchings 

Method. 
(R. N. Y. GO (1901) No. 2702: 753-4). 

1901. Waugh and Cununings. Apple Growing in Addison County. 

(Vt. Bui. 90: 31-36, Fig. 3). 

1903. Craig, John. 

(N. Y. Cornell Reading Course for Farmers, ser. Ill, 
No. 3, 1903). 

1903. Bedford and Pickering. Effect of Grass on Apple Trees. 

(Woburn Exptl. Fruit Farm, Rpt. 1903, pp. 56, pis. 3). 

1903. Emerson, R. A. Experiments in Orchard Culture. 

(Nebr. Bui. 79: 1-33, Fig. 12). 

1904. Hedrick, U. P. A Talk on the Apple. 

Mich. Extens. Bui. No. 1: 5-6. 1904). 

1904. . Mulching. 

(U. S. D. A. Farmer's Bui. 202: 8-12). 

1904. Causemann. Results of Soil Aeration with Orchard Fruits, 

&c. 

(Deut. Landw. Presse, 31 (1904) No. 72: 619-20). 

1905. Cox, U. T. and Green, W. J. A Straw Mulch in the Orchard. 

(W. Ya. Farm Rev., 13 (1905) No. J f : 18; reprinted from 
Stockman and Farmer). 

1905. Munson, W. M. Experiments in Orchard Culture. 
(Me. 122, pp. 181-204, pi. 1, dgms. 4). 

1905. Warren, G. F. Apple Orchard Survey of Orleans Countv. 
(N. Y. Cornell Bui. 229, pp. 461-499. Fig. 15). 



490 ANNUAL RRPORT OP Off. Doc. 

1905. Craig, J. Phases of Orchard Management in Wayne County 
as Discovered by an Orchard Survey. 
(West N. Y. Hort. Soc. Proc. 1905, pp. 54-64, Fig. 6). 

1905. Vergon, F. P. Grass Mulch for Apple Orchards. 

(E. N. Y., 64 (1905) No. 2874 : 137-8, Fig. 1). 

1905. Munson. Keeping Qualities as Affected by Culture. 

(Me. Bui. 122: 200). 

1906. Green and Ballou. Orchard Culture. 

(Ohio Bnl. 171, pp. 189-215, Fig. 18). 

1905. Walker, E. Suggestions upon the Care of Apple Orchards. 
(Ark. Bui. 91: 141-210, Fig. 18). 

1907. Green, S. B. Cultivation and Covercrops. 

(Office of Expt. Stations Bui. 178: 19-23, 1907). 

1907. Pickering, S. U. Boot Action and Bacteria. 

(Nature (London) 76 (1907) No. 1962: 126-7). 

1908. Pickering, S. U. Studies on Germination and Growth. 

(Jour. Agr. Sci. 2 (1908) No. 4, pp. 411-434). 

1909. Cummings, M. B. Tillage. [Orchard Survey Results]. 

(N. Y. Cornell Bui. 262: 295-300; also compare Cornell 
Bulletins 226 and 229 by Warren). 

1909. Collingwood, H. W. [An Account of an Experiment on Till- 
age vs. Sod Mulch in Hitchings' Orchard.] 
(Rural New Yorker, Oct. 23, 1909: 921. Oct. 30, 1909: 
941). 

1909. Bailev, L. H. Principles of Fruit Growing. 

(Copyright 1897, reprinted 1909, pp. 133-174). 

1909. Shutt, F. T. Control of Moisture in Orchard Soils. 
(Amer. Pom. Soc. Rpt. 1909: 32-41). 

1909. Taft and Wilken. Cultivation vs. Mulch. 
(Mich. Sta. Spec. Bui. 48: 320). 

1909. Hedrick, U. P. A Comparison of Tillage and Sod-Mulch in 

an Apple Orchard. 
(N. Y. State Sta. Bui. SW 77-132, pis. 8, dgm. 1). 

1910. King. Principles and Practice of Earth Mulches. 

(Rural New Yorker, July 2, 1910: 689-90). 

1910. Stewart, J. P. The Fertilization of Apple Orchards. 
(Penna. Bui. 100: 17-28. 1910). 

1910. . Tillage vs. Sod Mulch in Apple Orchard. 

(U. S. D. A. Farmers Bui. 419: 5-10. 1910). 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 491 

B. Cover Crops. 

1900. . Effects of Alfalfa and Grass on the Growth of Young 

Orchard Trees. 

(Hessiehe Landw. Ztschr., 70 (1900), No. 7: 78-9. Fig. 
1). 

1902. Craig, J. The Relation of Cover Crops to Depth of Freezing. 

(N. Y. Cornell Bui. 198). 

1903. Smith, C. B. Summary of Experimental Work on Cover Crops 

up to 1903. 
(O. E. S. Keport 1903, p. 555-58). 

1903. Pennv, C. L. Cover Crops as Green Manure. 

(Dela. Bui. 60: 3-43. 1903). 

1903-4. Hedrick. Relation of Plants in the Orchard. 
(Proc. of Soc. for Hort. Science, 1903'4). 

1904. Sandsten, E. P. Cover crops. 

(Wis. Rpt. 190.',: 252-57. Fig. 2). 

1904. Hedrick, U. P. A Sidelight on Cover Crops. 

(Rural New Yorker 43 (1904) No. 2862: 858, Fig. 2). 

1906. Emerson, R. A. Cover Crops for Young Orchards. 
(Nebr. Bui. 92: 3-23. Fig. 8, pis. 2). 

1906. Craig. In "Cyclopedia of American Horticulture," p. 388. 

(Copyright 1900, reprint 1906). 

1907. Hunt. Forage and Fiber Crops. 

(The Clovers, pp. 140-173. Cowpeas, soy beans, vetches, 
etc. pp. 241-274). 

1907. Yoorhees. Natural Agencies in Soil Improvement. 

(Pennsvlvania State Department of Agriculture Report 
for 1907, pp. 172-81). 

1907. Yoorhees. Forage Crops. 

(The Clovers, pp. 221-252, 1907. Cowpeas, soy beans, 
vetches, etc., pages 253-274). 

1908. Thornber. Orchard Cover Crops. 

(Wash. Station, Popular Bulletin 8, p. 1-4, 1908). 

1910. Hopkins. Soil Fertility and Permanenl Agriculture. 
(Pages 207-225).' 

1910. Penny, C. L. aud MacDonald, Margaret B., Crimson Clover; 
Its Rate of Gaining Nitrogen. 
(Dela. Sta. Bui. 86: 3-42. 1910 1. 

C. Irrigation. 

1894. Troop, J. Experiments with Small Fruits. Also Irrigation. 
(Indiana Bui. J f 8: 3-14). 

1897. Cranefield, F. Cold vs. Warm Water for Greenhouse Plants 
(Wis. Rpt. 1897: 317-20). 



492 ANNUAL REPORT OF Off. Doe. 

1899. Graham, J. I. Top-grafting and Irrigation. 

(Fruit Growers' Assoc. Ont. Rpt. 1899: 20-24). 

1899. McClatchie, A. J. Effect of Winter Irrigation of Orchards. 

(Also depth of Orchard-tree Roots). 
(Ariz. Sta. Rpt. 1899: 257-59). 

1900. Wickson. Irrigation in Fruit Growing. 

(Farmer's Bulletin, 116: 1-48, 1900). 

1900. Jordan, A. T. Effect of Irrigation, Fertilizers, and Excess of 

Nitrate of Soda on Vegetables and Fruits. 
(N. J. Rpt. 1900: 213-55, pis. 4). 

1901. Wickson. Irrigation on Field and Garden. 

(Farmer's Bulletin 138: 1-40, 1901). 

1904. Mead, Elwood. Preparing Land for Irrigation and Methods 
of Applying Water. 
(U. S. Office of Expt. Sta. Bulletin 1^5: 1-48. 1904). 

1904. Mead, Elwood. Review of Irrigation Investigations for 1903). 
(U. S. Office of Experiment Sta. Rpt. 1903: 469-502. 
Includes reports on irrigation of strawberries, 
nursery stock and certain vegetables). 

1906. Fortier. Practical Information for Beginners in Irrigation. 

(Farmers' Bulletin 263: 1-40. 1906). 

1907. King. Irrigation and Drainage. 

Copyright 1902, Reprinted 1907. 

1910. Lamson, J. L. Experiment in Orchard Irrigation. 

(Western New York Hort. Soc. Proc. 55: 49-59, Fig. 
5. 1910). 

1910. Fortier. Irrigation of Orchards. 

(Farmers' Bulletin J,0^: 5-36. 1910). 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 493 

VARIATION AND HEREDITY AS FACTORS IN APPLE PRODUCTION. 

This is a phase of our subject that has received comparatively little 
defiuite and continuous attention in the past, though it has been 
referred to many times and it is now receiving attention in a number 
of places. Of these may be noted the Canada Central Experimental 
Farm at Ottawa, the Experiment Stations of: New York (Geneva), 
.Maryland, Virginia, Illinois, Iowa, Indiana, Missouri, Arkansas, 
Kansas, Wisconsin, Minnesota, North Dakota, South Dakota, Ne- 
braska, Idaho, Oregon, and our present experiments at the Pennsyl- 
vania Station. 1 Besides this, in a very few cases, systematic work 
is also being done by private individuals. 

If improvement is possible in apples or other fruits through the 
means of variation and heredity, we can see no good reason why it 
should not become extremely important. These forces of variation 
and heredity are being utilized in the improvement of other crops; and 
why this should not also be possible in apples is not entirely clear. 

The difficulties in the way are essentially two. First, if the effort 
toward systematic improvement is made by the way of the seed, we 
are confronted by the extremely heterozygous condition of the gametes. 
This has iesulted from repeated cross-pollination for centuries, and 
is indicated in the well known conspicuous failure of most fruits to 
tome true to seed. It therefore seems necessary to devote much time 
to a study of the gametic characters of a given variety, and possibly 
to reduce their number, before any considerable, systematic progress 
can be made by way of the seed. 

On the other hand, if the effort toward improvement is made by 
way of cion-selection, we find ourselves dealing with so-called "pure 
lines'' or biotypes, in which we are informed that no important pro- 
gress by selection is possible. 

Despite these facts and apparently well-established principles, we 
are giving some attention to the second possible method of improving 
apple production, viz., by cion-selection. This phase of the problem 
naturally divides itself into two questions. First, do important 
variations occur between trees or parts of trees of the same variety? 
And second, if they do occur, are they heritable ; i. e., are they due 
to internal or to external causes? 

THE EXISTENCE OF IMPORTANT VARIATIONS IN APPLES. 

In answer to the first question, with reference to yield especially, 
we have brought together and compared a considerable amount of 
data from our own experiments and those of others. These data were 
originally obtained, in all cases, in connection with other kinds of 
experiments, but by comparing only the yields of trees that irere 
under apparently identical conditions, we have assembled the data 
shown in the following Tables, XL 1 1 to XLV. 

J For the general character of the work at each of these places, see article by S. A. Beach 
on "The Present Status of Apple Breeding in America," in American Breeders' Association 
Rpt. for 1909, pp. 28-36. 



494 



ANNUAL REPORT OF 



Oft". Doc. 



Table XLIL— INDIVIDUALITY IN BEARING OF APPLE TREES. 

(NEW, YORK). 

(Yields for 10 years and relative position of 6 trees in 1896 and during the 10-year period.) 



Tree. 



Yield, 10 yr., 
bu. 



Ratio. 



Percentage of Total Yield. 



Rank. 



Ifl-year 
Period 



No. 1, 

2, 


72.25 
125.50 
85.58 
64.98 
84.58 
121.0 




12 % 
21.2 
18 
11 
17 
20.8 


2 
6 
4 
1 
3 


13 % 
22.6 
15.4 
12 
15.2 
21.8 


2 
6 


3, 




4 


4, - 




1 


5, 

6 




3 
5 








2 &'6 


246.5 
137.2 


179.6 
100 










1 & 4 























Table prepared from data given by S. A. Beach in Geneva Bulletin 239: 218-19', 1903. The 
variety was Rhode Island Greening. 



Table XLIIL— INDIVIDUALITY IN BEARING OF APPLE 

TREES. (CAN A DA) . 

(Comparative yields in gallons, for 14 years of single trees in each variety.) 



Variety. 


Tree. 


Age 1908. 


Yields. 


Ratio. 


Wealthy, 2 

Wealthy, 2 


No. 4 

8 


13 
13 


154.25 
58.5 


263 
100 








1 
2 

7 


11 
11 

11 


753.5 
579.5 
163.5 


462 




355 




100 








1 
2 


19 

19 


501.5 
230.5 


218 




10O 








1 

13 


17 

17 


502.5 
209.5 


240 




100 












477.94 
165.5 


288 








100 











1. This table is prepared from data given by W. T. Macoun in Canada Experimental Farms 
Rpts. for 1905 to 1908. Yields arc stated in gallons in all cases 

2. Yields are for 10 years only, in this case. 



No. 20. 



THE PENNSYLVANIA STATE COLLEGE. 



495 



Table XLIV.— INDIVIDUALITY IX BEARING OF APPLE 

TREES. (MAINE). 

(Comparative yields of 10 highest and 10 lowest trees under similar conditions during 5 years.) 1 



Var ; ety. 



Baldwin, 



High Yielders. 



Tree. 



Total 
Yield. 



Low Yielders. 



Tree. 



No. 25 
42 
51 

81 
17 
20 
47 
88 
31 
32 



22.3 bbi. 

13.1 

16.3 

14 

13.5 

17.9 

17.4 

14.9 

13.5 

15 



No. 24 
43 
52 
74 
18 
26 
50 



Total 
Yield. 



6.5 bbl. 

4.8 

4.7 

4.4 

1.8 

3.3 

3.8 

2.2 

3.1 

3.4 



Totals. 



157.9 bbl. 



10 



Ratio, — 415.5 



38.0 bbl. 



100 



l . Prepared from data given by Munson in Maine Station Bulletins 122: 193-5; 139: 56; 155: 
131 and 137-38. 1905 to 1908. The trees averaged about 40 years old at the close, 1907. 



Table XLV.— INDIVIDUALITY IN BEARING OF APPLE 
TREES. (PENN8 YL V. 1 V I A). 

(Comparative yields of 10 highest and 10 lowest yielding trees, under similar conditions, In 
each of 20 eases involving 11 varieties, during three years.) 





















n 


BO 




acr 




& 


Variety. 


2 


yielde 




s per 


o 


p. 




em 


fc 


jes 


s 


o 


X 




H 


o 


M 


X 




w 




►-1 


W 


w 


K 



215 
215 
216 
216 
217 
217 
218 
218 
219 
219 
219 
zxO 
221 
221 
336 
336 
336 
338 
339 
339 



Stayman Winesap, 

York Imperial, 

Jonathan 

York, 

York, 

Gano 

Albemarle 

York, 

York. 

Jonathan 

Ben Davis & Gano 

York, 

Baldwin, 

N. Spy, 

Grimes, 

Smokehouse, 

Stayrnan, 

Baldwin, 

Baldwin 

Fallawater,. 



-Average (20 cases, 11 varieties), 



lb. 

665.83 
1138.75 

6279. 

7142.5 
14667.75 
11752.75 

4626.76 

2731.75 
830.5 

1539 

1115. 

9798.5 
26671.75 
31315 

1557.5 

2413.5 

1209 
13439.5 

4123.75 

2333.5 



7267.5 



lb. 

59 
164.25 

1685.5 
1640 
1858. 
1614.5 

137. 

129.5 

247.25 
85 

6410. 
11 158 
122 
335.5 

2 

3507. 

626 

137 



1729.6 



lb. 

606.83 

974.5 

1593.5 

5502.5 
12815.75 
10138.25 

1489.75 

8602.26 
814.25 

1291.75 

1030 

5433 
20261.75 
19850.5 

1435.5 

2078 

1207 

9935.5 

3497.75 

2196.5 



bu 1 . 

42.4S— 
68.2] 
321.54 

385.17 

897.1 

709.67 

314.28 

182.15 

57.— 

90.42 

72.1 

380.3 

1418.32 

1389.95 

100.48 

145.46 

84.49 
495.44 
2i4.84 
153.75 



377.65 



11.28 
6.932 
3.725 
4.355 
7.919 
7.28 

33.76 

21.08 

51.11 
6.224 

13.12 
2.244 
4.16 
2.733 

12.76 
7.104 
(604. 51 
3.832 
6..W 

17.03 



11.754 



1 . This computation is* based upon an acre of 35 trees, and 50 pounds of fruit per bushel. 
The actual number of trees per acre waa greater in most cases. 

35 



496 ANNUAL REPORT OF Off. Doc. 

From these tables it is quite evident that very marked variations in 
bearing do exist among apple trees, even though they be of the same 
age, of the same variety, in the same orchard and apparently under 
identical treatments. Thus in Table XLII, during 10 years, two 
Ehode Island Greening trees produced over one and three-quarters 
times as much fruit as two others adjacent and under the same re- 
spective treatments. Among the six trees of this table also, the 
difference in productiveness seemed to be a rather permanent char- 
acter of the individual tree since they retained practically the same 
relative productiveness throughout the 10-year period as they had in 
1896, the fourth year. 

In Table XLIII, during 11 years, four trees have averaged nearly 
one and two-thirds times as much fruit as four others, with individual 
constrasts as high as 4.6 to 1. In Table XLIV, during 5 years, ten 
Baldwin trees produced over four times as much fruit as ten others 
adjacent and similarly treated, with individual contrasts as high as 
7i to 1. 

In Table XLV, the ten highest yielding trees in each of 20 different 
cases, have averaged 4i times as much fruit as the ten lowest trees 
in the same varieties, with individual 10-tree contrasts running as 
as high as 50 to l. 1 Some of these higher differrences are attributable 
to the youth of the trees, young trees being always more or less erratic 
in their bearing. 

In general, however, the average differences indicate an indisputable 
tendency to greater yields in some trees than others. It will be ob- 
served that in the trees of our experiments, although some of the yields 
are comparatively light, this difference has amounted to 377.65 bushels 
per acre during the 3-year period, or about 128 bushels per acre per 
year, — a gain which is obtained practically without cost. 

Nature of These Variations, and Present Evidence on Their Inhcri- 

tability. 

It seems hardly possible that all the differences observed here are 
due to environmental influences. In the large number of trees con- 
sidered it would seem that at least some of them are higher yielders 
because of inherent or internal variations in this respect. As we 
shall see later, unquestioned vegetative variations in other respects, 
such as color and season of fruit, color of foliage, and habit of growth, 
have occurred among horticultural plants, a number of which have 
been fairly steady in their propagation. Variations in yield can 
hardly be essentially different from those of color. The problem, 
therefore, is to isolate the inherent high yielders from the groups of 
trees that have been definitely shown to be relatively high producers 
during a series of years. 

This of course can only be done by propagative trials, which brings 
us to the second of our questions stated above. Upon this phase, 
we have very little positive evidence to offer, so far as yield is con- 
cerned, though there is considerable negative evidence available. 

We are now testing this inheritance phase fairly extensively, by 
comparing ordinary nursery trees with other trees planted at the 
same time and topworked with cions said to be from superior trees. 

Hn one case, in experiment 336, a contrast of 604 to one is shown. But this is clearly due 
to the youth of the trees, (ages shown in Table IV), and this relative yield is not included in 
determining the final average rates. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 497 

We had no data such as that given in Tables XLII to XLV, when 
this test was started, so that in nearly all cases we have had to rely 
upon the general observations of practical orchardists for evidence 
of superiority. Thus whenever we have learned of a specially noted 
individual tree, we have obtained cions from it, if possible, and 
worked them into our test. We now have under trial some t!i possible 
strains of 25 varieties obtained in ibis manner. This is to be sup- 
plemented by lests of .cions from high ami low yielding trees of more 
definite previous history as opportunity permits. 

The evidence available elsewhere upon the heritability of superior 
characters in apples is very hugely negative. Notes on the results 
of trials have been kindly furnished us in letters from a number of 
persons, as noted below. The essential portions of these letters are 
as follows : 

(1). Abstract from letter of Dr. J. C. Whitten, Missouri Experi- 
ment Station, March 1910. 

"Fifteen years ago I began taking observations and measure of the crop from the 
most productive and the less productive trees in a Ben Davis orchard on the Ex- 
periment station -rounds here. At the end of three esasons, I took scions from 
the Ken Davis tree which for a period of three years proved to be the best pro- 
ducer year after year, and also from the Ben Davis tree in the same orchard which 
was the poorest producer for the period of three years. Of course, we eliminated 
from consideration trees that were undersized, broken, diseased, or from any 
other environmental influence in the orchard, made it evident that their pro- 
ductiveness or unproductiveness was due to external conditions rather than to any 
possible inherent qualities of the trees themselves. 

"This past summer we secured the first full crop of fruit which has yet been 
borne upon those trees, they having fruited only very sparingly here and there 
in previous seasons. We have found no difference whatever in the productiveness 
of the trees propagated from the good producer and those propagated from the 
poor producing tree. The quality, size and quantity of the fruit is equally as 
good on those trees propagated from the poor producing Ben Davis. In planting 
these trees out in the orchard we have alternated a good producer and a poor 
producer in the rows so as to make their environmental conditions as near alike 
as we possibly could. From this one experiment, of course, I do not mean to 
conclude that there is nothing in scion selection. Of course, the poor producing 
apple tree may have been a poor producer because of come environmental condition 
which we could not see. The good producer likewise may have had some favored 
condition of environment which was not visible to us. It seems to indicate, how- 
ever, that one cannot be sure every time that a good producing tree is out-fruiting 
its fellows because of inherent qualities alone. Or else if it has these inherent 
qualities, it might not always be capable of producing them into budded off- 
spring." 

(2). Abstract from letters of Joe A. Barton, Mitchell, Ind., March 
1909, and February 1911. 

"I have been trying to improve apples by selection in the Indiana Experimental 
orchard for several years. First, I asked if the stock worked any change on the 
cion. Yellow Transparent was grafted into a wild crab. Leaves of the Trans- 
parent were removed later, so that apple had to grow on sap prepared by crab 
leaves ahme. Result, perfect Yellow Transparent fruit. 

2. "Deep red Ben Davis grafted into light colored Ben Davis. Fruit from grafts 
all light colored. 

3. "Small poor-quality Rambo grafted on same stock with high-quality Rambo. 
Result, both good alike. 

4. "Little green Genet (Ralls) on tree with large red Genet. Apples all the 
same. 

5. "Ben Davis. Jonathan and Grimes cions from nursery rows, — the two former 
having been re-propagated thus, for over 40 years, — were grafted on same s!ock 
with cions from good hearing tree. All bore alike. 

t>. "Grimes from a regular annual bearer with cions from two very shy bearers. 
All fruit alike. 

7. "Water sprouts from Benoni and Yellow Transparent grafted on same stock 
with cions from bearing wood. All bore alike. 

32—20—1910 



498 ANNUAL REPORT OF Off. Doc. 

8. "Warfield Strawberries grown and selected for 12 years by the late R. M. 
Kellogg, were planted in alternate rows with Warfield from our own patch that 
had been propagated from tips only, for the same time. Result, no one could 
see any difference." 

(3). Abstract from letter of L. L. Springer, Edenville, Pa., May 
1911. 

"A number of years ago, one Salway peach tree appeared among four rows of 
trees in one of my orchards that was far superior to all others. It bore an- 
nually, the fruit was larger, more highly colored and better in every respect. I 
propagated from this tree for three years, when I found to my great disappoint- 
ment that there was no improvement over other Salway trees. 

"This tree stood on a little knoll perhaps 18 to 20 inches higher than the sur- 
rounding ground. Hay and grain did not grow on this elevation and I had sup- 
posed it be too hard and poor to grow anything. And yet the difference seems to 
have been in the soil." 

(4). Abstract from letter of Herbert P. King, Trumansburg, N. Y., 
May 1911. 

"Some years ago we noticed one limb of an Elberta peach tree that ripened 
its fruit about 10 days earlier than the others. After noting this for three years, 
we budded a few trees from this limb, and their first fruit appeared last year. 
It ripened all the way from two weeks ahead of ordinary Elberta to the same time 
as the latter. We have now budded a second time from the earliest ripening 
limbs, hoping to fix the quality of early ripening." 

(5). In an article by W. J. Wright, of The Pennsylvania State 
College, in the Rural New Yorker, 1911: 155, Mr. J. W. Kerr of Mary- 
land is quoted as follows: 

"A test, with trees propagated from a tree of Wild Goose plum that produced fruit 
notably large and fine as compared with trees propagated from the other extreme, 
demonstrated clearly that, under like conditions of soil, both were average Wild 
Goose plums. No more, no less." 

It will be seen from the above communications that rather scant 
evidence of the value of selecting cions from trees with superior 
or desirable qualities, is available as yet. In fact the "pure line" 
or biotype exponents seem to have the best of the argument thus 
far. 

It is not yet finally proved, however, that selection does not have 
value for the purposes indicated. This negative evidence is valuable 
in showing that the size of the problem is greater than is generally 
supposed. But there are some inklings of final success, in the peach 
work by King for example, and especially in some of the apparently 
heritable variations in color referred to below. 

The principles involved do not differ materially from those of 
nurserymen in discovering and propagating new vegetative types 
of ornamentals and other plants. For this reason, Ave have observed 
operations in a number of nurseries, and the following statement from 
the experience of the Hoopes Brothers & Thomas Company, of West- 
chester, Pa., is representative. 

"We are constantly finding, among trees and shrubs, sports that are different 
in character from the original tree, either variegated leaves or different colored 
leaves or different forms of growth. A few of these like the Rivers Purple 
Beech, Schwedleri Maple, etc., have become fixed and do not change, but most 
of the others are liable to go back to the original form; for instance, the Tom 
Thumb Arbor Vitae is one of the best examples. It is a variety of the American 
and the growth is entirely distinct. Unless you are familiar with it, you would 
not think it was an Arbor Vitae, and yet generally in a few years it goes back 
to the original species. The variegated Privet is another sample of these sports. 
It holds its variegation for a few years, and gradually you will find a shoot com- 
ing up green which increases each year until the variegation has disappeared." 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 499 

It is not unlikely thai some of these conditions will be found to 
obtain in the vegetative variations of apples and other fruits. 

Incidentally, however, the indicated behavior of Trivet, so far 
as albino variegation in foliage is concerned, is apparently explain- 
able. The particular phase of environment or nutrition concerned 
in this and similar cases is probably calcium supply. As brought 
out in connection with our discussion of mineral nutrients, on page 
453 one of the things found in certain analyses of foliage is that 
albino leaves contain much less calcium than normally green ones, 
the reduction often being to less than half the lime content of the 
latter. 

This suggests the connection stated above, that albino leaves are to 
be attributed to lack of calcium, the lack arising either as a result 
of its actual deficiency in the soil or as a result of defects in the 
nutrition of the plant shoAving the variegation. In corroboration 
of this view, the 'following experience of J. P. Pillsbury, while in 
charge of the landscape work at this Station, is of interest. 

About 1896, it was decided to change some 15 plants of a variegated 
form of Sedum telephoides from a border planting to another situa- 
tion about 75 feet distant. These plants had always shown markedly 
variegated leaves and stems of the albino type, and the most varie- 
gated plants were chosen. The soil in the new situation was of a 
stiller clay than in the previous border, and therefore was limed 
heavily to improve its texture. 

As a result, the transferred plants within a year or two lost all 
traces of their previous variegation and so far as observed they have 
maintained a deep green foliage and vigorous growth until the cur- 
rent season, 1911. During this season, a few plants near the middle 
of the border are again showing traces of variegation. No lime has 
been applied to the plot since the original application, 15 years ago. 

While this has only an incidental bearing on our particular prob- 
lem, yet it shows the possibility of more definitely isolating the par- 
ticular environmental features that are at present clouding some 
of our results. 

BIBLIOGRAPHY: ON CION SELECTION AND OTHER PHASES OF 
APPLE BREEDING. 

Some of the more important papers bearing on the improvement 
of apples by breeding are as follows: 

1900. Hitchcock, A. S. Plant Breeding by Bud Selection. 
(Amer. Gard., 21 (1900), No. 2GG, p. 59). 

1902. Kellogg, B. M. Bud Variation in the Strawberry Plant. 

t Paper read at the International Conference on Plant 
Breeding and Hybridization at New York, N. Y., 
Sept. 30 to Oct. 2, 1902). 

1902. Powell, G. T. The Value of Improved Methods in the Propa- 
gation of Fruit Trees. 
(Proc. N. J. Hort. Soc. 27 (1902): 125-35, Fig. 2). 

1902. Corbett, L. C. Improvement of Boses by Bud Selection. 

(Piper at Intern. Conf. on Plant Breeding and Hvbridi- 
zation, N. Y. City. 1902 . 



500 ANNUAL REPORT OP Off. Doc. 

1904.' Jordan, A. T. Improving Fruits bv Bud Selection. 
I Aiuer. Agr. 74 (1904) No. 9: 160). 

1905. Blacknall, O. W. Bud Variation. Facts That Trove Its Oc- 
currence. 
(Country Gent. 70 (1905) No. 2717: 179). 

1905. Macoun, W. T. Individuality of Fruits. 

(Kept. Can. Expt. Farms, for 1905: 105-6). 

1905. A Symposium. Apple Scions from Bearing Trees: Influence 

of Stock. 
(Rural New Yorker, 64 (1905), No. 2907, p. 741). 

1905-8. Munson, W. M. Variation in Fruitfulness of Individual 
Trees. 
(Maine Bui. 122: 193-5; 139: 56; 155: 134 and 137-8). 

1906. Ewert. Flower Biologv and Productiveness of Fruit Trees 

(Landw. Jahrb., 35 (1906) No. 1-2, pp. 259-287, pis. 2). 

1907. Card, F. W. Cion Selection and Blooming Dates. Also Prun- 

ing Experiment at Planting Time. 
(R I. Bpt. 1907: 211-14; 220-65, pis. 7). 

1908. Powell, G. T. $1000 an Acre from Pedigreed Trees. 

(Countrv Life in Amer. 13 (1908) No. 5: 504-6, 538, 540, 
Fig.' 12). 

1909. Beach, S. A. Report of the Committee on Breeding Tree and 

Vine Fruits. 

(Amer. Breeders Asso., Vol. 5, p. 28, 1909). . 

1909. Ballon, F. II. Bud Sports in Apples. 
(Ohio Give. 94: 1-70, Fig. 20). 

1911. Wright, W. J. What About Pedigreed Trees? 
(Rural New Yorker, p. 155, 1911). 

FACTORS INFLUENCING SIZE IN APPLES. 

We have seen above that, under certain conditions at least, the 
size of apples can be influenced by fertilization and also by cultural 
methods. Their average size is also evidently intluenced by inherent 
or internal causes, as shown by the differences in size between varie- 
ties, and also probably by some of the differences between individual 
trees of the same variety. 

But we have also noted cases in which none of these factors had 
their usual effect. In these cases, other factors evidently cut across 
the results, and exerted the dominant influence. Among the latter 
influences, the size of the crop on the tree in proportion to the avail- 
able moisture supply, or in other words, the amount of moisture 
available per individual fruit, has seemed to be the most potent. 
On this account and also because of its relation to the value of thin- 
ning, Ave have given some special attention to the latter factor. 

Considerable data on this, — some of it merely eliminating other 
factors, — is given in our tables above. In t lie present space, we shall 
confine our attention to data obtained in connection with an orchard 



/^Onpbcr of Appl© a or^Trcc 
S £ S $ & £ 



^ 



33 






NO 


■o 


INS 


a 



o 
< 

2 

10 

rr 



























z 1 






















































































































































































































^~- 


--- 


1 
































*», 










v . 
























--« 


'•-. 




























c 






















, ' 


-- 


-"- 1 
























\ 




7 
















j 


^ 
































\ 




n 





















1 


- 


^ 


— 




























<-* 




























V 


















$ 

> 








cj 




























£> 
























rr 


























'll 






















\ 




'J 
S3 


























O 


cD 


















6 




— 1 




n- 
"1 




























? 
























IS 
























er 


i5 


















































£. 


rt 


















































s< 


D 


















'A 




































13 









































































































































































































































































































































































































































































































































\ 







































































































































yj Ob --1 (T> Oi > lu 

Average weight of Apples 17 oz. 



5feo 






















£>ALDVin 
































































1 










6 


55. 


5zo 


















































































































48o 


















































































































Mo 


















































































































>V>0 


















































































































3fco 


















































































































£ 








1 


\ 
















































D> 




\ 




\ 


\ 


































\ 














O 

*0 28o 




\ 




\ 


\ 


-A 


.\rc 


ra 


ge 


w< 


:ig 


bt 


9* 


Op 


pic 


►,s 




























\ 




\ 


\ 


( 


t\a 


av 


\<Z£ 


t 


be 


\o\ 





















\ 












a. 




\ 






\ 


































\ 












<£ 240 




\ 


/ 
































\ 




/ 

1 


1 












0* 
L 200 






































\ 
























































\ 


/ 


















XI 
^160 

IZo 






































i 


/ 














/ 






































/ 


















/ 
























































1 




























































ao 


















































































-n 


am 


be. 


r o 


H 


ra 


its 


o 


al 


re 


e 
































































































































o 1 












/ 















































o 

3-q. 
a- 

4 



5? 

G W 

2 



« 



iCelatiop between size of crop a^d Qveraa<?. wciqtyt of apples 

Fig. 23. 



Wo- SO. THE PENNSYLVANIA STATE COLLEGE. 501 

fertilization experiment started al the New Jersey Station in 1896, 
al which time the trees were planted. This experiment has there- 
fore been running for 15 years, during the hist 9 of which some fruit 
lias been borne. 

The experimeul consists of three plots, each containing two trees 
of Smith Cider, Baldwin, King, Jonathan, Oldenburg, and Graven- 
stem.' Plot I receives nothing; plot II annually receives 500 pounds 
per acre of an even mixture of bone, muriate of potash, and acid 
phosphate; plot III receives the same treatment as plot II, with 
the addition of 150 pounds per acre of nitrate of soda, the applica- 
tion of the latter apparently having begun in 1904, when bearing had 
become fairly well started. As an experiment in fertilization, it 
has apparently not been considered important at the New Jersey 
Si at ion on account of the small number of trees of each variety, some 
of which also have died and been replaced. 

The experiment is of interest to us, however, especially because 
of the fad that records of both the number and weight of apples per 
tree have been kept since the experiment started, with the exception 
of the year 1910. In that year, the weight of 200 average fruits 
from each tree was obtained instead. 

While not ideal in every way, these data evidently furnish a basis 
for studying the relation between size of crop and average weight 
in apples. The objections are chiefly in the youth and varying age 
of the trees, the latter gradually increasing throughout the period 
considered, and in the fact that the results were not all obtained 
m one season, thus introducing differences in rainfall. 

The presence of the fertilizer also is a disturbing factor, but the 
extent of its influence is shown in a table later. 

In utilizing the .lata, we assembled the figures for each variety and 
calculated the average weights of the apples on each tree during the 
period covered, from 1902 to 1910. 2 The relation existing between 
these average weights and the number of fruits on the tree was then 
studied by means of curves, the results being shown in Figures 9 2 
to 26. 

In preparing the curves shown in the figures above, the average 
weight of fruits was arranged on the ordinal axis and made to in- 
crease downwards, since the relation, if present, would naturallv 
be an inverse one. 

The curves show that no definite correlation existed under the 
New Jersey conditions in any of the first thiee varieties plotted In 
hgures 25 and 20, however, some correlation is observable in the 
hitter stages of the curves, i. e., after the number of fruits on the 
tree has become large.— 12(10 to 1400 or more— some inverse relation 
appears between average size of fruit and size of crop on the tree 
Hits relation would doubtless be clearer, were it not for the disturb- 
ing factors mentioned above. 

This means in general (hat if one thins an apple 1ree of even mod- 
erate size before the number of fruits has reached about 14(H) or 
more, he can hardly exped to increase the size of the remainine 
fruit, and the net elfect of the thinning will be an actual reduction 

wrTrilTL™^** yle J ed S ° mt ' e and S ° irre Sular,y that it is not con-ldwdl^ur 

m: t v 6 sa.'B .SSflSK Jer6ey Re;,orts for 1903 ,ol90S - «* fr ™ *™«°«» 



502 



ANNUAL REPORT OF 



Off. Doc. 



in total weight of apples, at least for that year. The exceptions 
to this may appear in varieties with fruit of unusually large size, 
or in seasons or locations that are exceptionally dry. 

It also means that while the crop-size influence becomes operative 
and probably dominant after the number of fruits on the tree has 
passed a more or less definite critical point, yet below this point 
there is opportunity for other factors to exert their influence. It is 
here that such factors as fertilizers, cultural methods, moisture sup- 
ply, and heredity have their opportunity to affect the average size 
of the fruit. These latter factors also evidently may co-operate in 
such a way as to raise the critical point somewhat, but in the end 
the crop size influence, or in other words the amount of moisture 
available per individual fruit, is always the dominant one. 

In this discussion, we have assumed that the variety was properly 
located in respect to temperature and length of growing season. 
These factors also are likely to have an influence, as pointed out by 
Shaw at the Massachusetts Station, to whose work the reader is 
referred. 1 

The effects of pollination and number of seeds per fruit may also 
be important, as pointed out by Ewert and Miiller-Thurgau in Ger- 
many, and to their work the reader is also referred. 2 

Fertilizer Effect on Size of Apples in New Jersey. 

As shown by the curves, the size of the crop in these trees was not 
great enough to materially affect the size of the fruit except in a 
very few cases. We should therefore expect to find some influence 
from fertilizers. To determine this we have prepared Table XLVI. 

Table XXLVI.— INFLUENCE OF FERTILIZERS ON AVERAGE, 
GENERAL RELATIONS OF LIGHT TO COLOR. 

(Calculated from New Jersey Results for 9 years). 3 



Variety. 



I. 

Nothing. 




ITT. 

NPK. 



Baldwin, 6.13 oz. 

Jonathan, -- i 3.97 

Tomkins King, — ] 6.47 

Oldenburg - I 3.07 

•Smith Cider, - - 3.35 



6.12 Oz. 
4. -46 
7.34 
3.12 
4.18 



Average weight, 
Ratio, Size, ... 



4.e 

100 



5.00— 
108.7 



Total yields, 5093.7 1b. 10831.8 1b. 8337. lb. 

Ratio, yield 100 212.9 163.8 

Ratio, yield, - - i 130— 100 



iShaw, J. E. Variation in Apples. Mass. Station Report, 1910, Part 1, pp. 194-213. 

2 Ewert, R. Parthenocarpie bei der Obstbaume, Landwirtschaftliche Jahrucher, Berlin, Vol. 
38: 767-839, 1909: also Ibid, Vol. 35: 259-287, 1906. Also see article by Miiller-Thurgau on "In- 
fluence of Seed upon Size, Shape and Color of Grapes." Landw. Jahrb. der Schweiz, Vol. 12: 
1898. 

3 This table gives the average of the average weights of fruit for each variety in each year from 
1902 to 1910. It is calculated from the data given in the New Jersey Reports for 1903 to 190S, 
and in letters from M. A. Blake for 1909-10. 










un 
r 





r of 

o 
6 


Applet 


o 
i 


17 1 ree 


j 


0> 

















i» 


B 




'• 
































X 


































































































i» 












£ 




















































/ 


3 1 


3 























































in 






















































§ 


§ 




























5" 


























IT 

rr 


10 

ST 




























5 


























R 

n 































■q 


1 




12 




















vi 































e 






c 






















~o_ 




























?: 






f 






















u> 




























ra 
o 






4 
























































-I 


















































N 


1 




E 

rr 


















































fc 


I 























































"-f 


\ 




M 
















L 


































o 

-1 


1 




















v 


s 





































^ 






















^ 


\ 




























O 
























-- 


*— 


-«- 




























o. 
























- — . 


• 


— — 


— 


























< 
























































1 
























































ID 
























































? 
























































ft 
















































































































"ft 
























































Q 
























































T3_ 
























































ft 
0> 














(A 


bo 






















































<n 


















































































































































i 




















































■ 




K 





o 

r 
Pi 

G 





^ 0» N *-> 

Average weig^ of Apples ip Oz. 



Jo^aTmaa 



















































































































































































































































































































































































































































































































































































































































































A 


ve 


rac 


l« 


W<2 


\qY 


it* 


>J< 


PF 


le; 


i 




























/ 


(H 


za^ 


fie. 


&tl 


>cl 


3W 


J 
































I 














































V 


V 
























s 


X 










































































































/ 






































/ 


\ 












































/ 


\ 














































\ 














































i 
















































\ 




/ 












































i 














































/ 














































/ 














































/ 
















































































































/ 


































































































































f* 


em- 


i be 


rc 


H 


rcii 


ts 


09 


fcr. 


^G. 
































































































































































































a 















































fcglatiop between size of crop ar)6 overage weight of apples. 

Fig. 25. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 503 

As stated earlier, tbe total crop yields here are not strictly com- 
parable because of trees being out or replaced in some of the plots. 
They are included in the table, however, for the ligb.1 (hey throw upon 
average size. It will be observed thai a fairly distinct effect appears 
on size in both fertilized plots, especially when the increase in crop 
is also considered. The influence appears to be greater in plot III, 
where nitrogen lias been added to the materials used in plot II. 

This may be because nitrogen really increases the size of the fruit, 
in normally moist seasons. In our own work, however, as shown 
in Table XXXII, the nitrogen influence has apparently been rather 
harmful. We suspect therefore, that the increase in plot II of Table 
XL VI would really be greater than that shown in plot III, if it 
were not for the depressing influence of the :*>() per cent, greater yield 
in the former case. 

FACTORS INFLUENCING COLOR IN APPLES'. 

In Tables XXX to XXXII, XXXV to XXXVII. an XL together 
with their following discussions, we have seen something of the de- 
tailed effects of various external factors upon color in apples. It 
remains for us to develop some of the broader phases of this subject, 
to present some additional data, and to show the relation of the 
various detailed effects to the main principles governing color in 
apples. 

General Relations of Light to Color. 

In apples, so far as the fruit is concerned, there are but two colors 
to be considered, — yellow and red. Physiologically, the former is 
connected with colored bodies in the superficial layers of cells. It 
develops independent of light, and its intensity depends merely 
upon the degree of maturity or ripeness. The hitler, however, is a 
constituent of the cell sap. It is capable of being influenced by a 
number of agencies, and its intensity is dependent primarily upon 
the amount of light that is received during the later stages of ma- 
turity. 

This relation to light is not true of all red colors in plants. The 
reds and allied colors of radishes, beets, truffles, potatoes, and car- 
rots develop independent of light. 1 The same is true of the flower 
colors of tulips, crocuses, and cucumbers. The chlorophyll in algae 
and in young conifers is also produced independent of light. 

On the other hand, the colors of flowers in Crassula 2 and of leaves 
in Coleus, 2 and most reds that are found in cell sap are apparently 
developed only with (he aid of light. The importance of light, there- 
fore, in the production of red colors in apples is naturally to be 
expected. 

An Experiment on tlie Relation of Light to Color in Apples. — ' 
To determine whether anything else was involved in this development 
of reds within a given variety, and especially whether these colors 
could be developed in the presence of light independent of anything 
that might be contributed by the sap from the tree, in the fall of 
-1909 we made a test of the effect of light upon apples after they 
were picked. In this test some 200 York Imperial apples were sep- 

1 See Jost's Plant Physiology, p. 308. 

2 See articles by Camille Flammarion in the Experiment Station Record, X: 103-114; 203-213. 



504 ANNUAL REPORT OF Off. Doe. 

arated into four lots of equal size, each lot containing approximately 
the same amount of color at the beginning of the test. Two of these 
lots were arranged to test the effect of sunlight and two the effect 
of electric light ; one of the lots in each case being darkened and all 
other factois being kept essentially uniform. 

The results of the test in brief were that the lot exposed to sun- 
light increased in redness by about 35 per cent., while in no other 
case was any definite increase observable. In some cases an apparent 
increase in the brightness, though not in the extent, of the redness 
was observed. But this seemed to be due essentially to the coming 
up of the yellow colors, thus increasing the contrast. 

This test therefore gives us two facts,— first the importance of sun- 
light, especially in connection with maturity; and second, the fact 
that color is apparently independent of anything contributed by the 
cell sap, at least after normal size is reached. To obtain high color, 
however, it is desirable to maintain connection with the tree as long 
as possible, because of the unfavorable effects upon keeping quality 
that result from any considerable exposure of the fruit after picking. 

The Dominant Influence on Color in Apples and Its Relation to 
Known Facts. — Maturity in sunlight on the tree, therefore, is the 
dominant influence affecting the color 1 of fruit in apples. And, so 
long as both maturity and light are operating, anything that tends 
to hasten or increase either will promote color, while factors tending 
to retard or decrease either will injure it. 

The relation of this principle to certain known facts is of interest. 
Thus we know that manure and nitrogen applications, heavy soils, 
and excessive cultivation, all tend to decrease color; Avhile light 
soils, sod or sod-mulch and possibly phosphate and potash applica- 
tions tend to improve it. These differences are all readily accounted 
for on the basis of their relation to maturity, though some of them 
also indirectly affect the amount of light. The first group of factors 
evidently tends to retard maturity, while the second group hastens 
it. We also know that dense tree-tops, heavy foliage, and early pick- 
ing of fruit give us reduced color, while the reverse conditions favor 
it. These effects are evidently due to modifications in the amount of 
light, and in one case also the degree of maturity is affected. 

Effect of Iron Applications. 

The idea that iron in the soil or iron applications have some definite 
relation to color in apples has long been present in horticulture. 
We have referred to this before in our discussion of mineral nutrients 
and we have yet to give the experimental evidence. 

No work with this element has been done as yet in our experiments. 
It has been applied, however, in the form of iron sulphate, both at 
the Missouri Station and at Wye College in England. At the former 
Station, better coloring was reported on both fruit and foliage of 
trees receiving the applications, but the leaves and peelings con- 
tained less iron than those of the checks. The time and amounts 
of the applications are not reported. 2 

The work at Wye College was done on tiees planted in zinc pots, 
and the iron sulphate applications were made in connection with 
complete fertilizers. In their work, the iron had no perceptible 

1 "Color" here and elsewhere in this discussion refers to the reds unless otherwise specified. 
2 Schweitzer, P. Mo. Rpt. 1896: 82-83. 















v3/MTn 


Cip^c 
































































































































Z7<"> 




































































































































































































































































ZZSo 


































































































! 




Zioo 


















































1 












































/ 






































































































/ 




















































// 


s 




?. 


(9 


































• 










// 


N 


\ 




o 












































/ 




s 
















A: 


■/ei' 


a< 3 


CZ VM 


aic 


Wt 


Pf 


apf 


sle,^ 












< 


/ 








o 
















<H 


zm 


l<Z5 


tb 


<zlo 


w) 
















\ 


f 






=> 


>0 




















































c_ 




















































< 




/ 
































































































4 


l2oo 




















































L 

9 




















































.£< 




/ 


















































/ 
















































»» 


/■ 


71 


irpl 


ar 


*i 


■rti 


ta 


}p t 


r<z« 


> 




















































r"' 




















































































6oo 
























































































































































45o 




































































































































































































































































o 





















































< 



K^latiop between size oj- crop aipd overage wciqt^t of appls; 

Fig. 26. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 

effect on color. The same was true of potash. In the case of phos- 
phoric- acid, however, they reported "highly colored" apples. 1 

These results are apparently all that are now available on the 
experimental use of iron salts upon apples. They are evidently 
inconclusive, and our present altitude is that as vet the use of iron 
salts as a fertilizer has nut been found to have value in increasing 
color iu applies. This is rather to he expected, since iron is required 
in relatively small amounts, as indicated above in our composition 
tables; ami it is almost universally present in orchard soils in suffi- 
cient amounts. 

An Experiment with Fertilizers upon Color of Flowers. 

Some work done in Rhode Island, on the effect of certain fertlizers 
on the color of flowers in a number of herbaceous plants, is of interest 
in this connection. 2 This experiment was run for two years, in 
1901-02. The effect of nitrate of soda, muriate of potash, and sugar, — 
all applied at the rate of 1001) pounds per acre, — was tested, the 
fertilizers being applied in July. 

The results were that many of the plants were injured on the 
plots receiving- the nitrate and muriate, and no influence whatever 
upon color as a result of the different applications could be observed 
during either season.'- 

An Effect of Certain Sprays on Color. 

Most of the effects upon color indicated above could be fairly 
readily explained. An effect that we have observed this past season 
on the relation of certain sprays to color in peaches is less evident 
in iis explanation. This effect we have referred to elsewhere, 4 and 
it has also been observed by others. It consisted in an extremely 
brilliant increase in the red color of peaches on certain plots in 
which considerable arsenical injury had occurred. 

This increase in color was probably due to a not unusual stimula- 
tive effect exerted by the arsenical poison, when present in less than 
killing strengths, coupled with the decreased foliage which admitted 
more light to the fruit. 

We have observed no effect similar to this on apples, though it 
possibly may be present. 

Influence of Variation and Heredity on Color in Apples. 

In the discussion above, our attention has been confined chiefly 
to environmental influences upon color in apples. The influence of 
internal factors, however, is fairly clear in this connection. 

The existence of such factors is obvious in the differences in color 
between such varieties as Baldwin, Mcintosh and Jonathan, on one 
hand, and Rhode Island Greening, Albemarle and Yellow Transparent 
on the oilier. The important question, however, is how have these 
differences appeared. 

^ard. Chron. 3 Ser., *> (1901) No. . 

".Card & Stene. KtTeet of Fertilizers upod the eolor of Flowers. R. I. Sta. Rpt. 1903: 213-14. 
■Also see article by Blake on "Factors which Determine Color in the Forcing of Roses." Proc. 
of SOC. for Hort. Science. I'.lln. pp. I',' 28. 

wart. .7. P. The smmiNT Spraying of Peaches. Pa. state Hort. Asoc. Rpt. 1911* 
181-195. Also, Aincr. Pomological Soc. Rpt. 1911: :?si-292. 



506 ANNUAL REPORT OF Off. Doc. 

Most of them have doubtless come from variations by way of the 
seed. There is evidence, however, that at least some of 1hem have 
come from variations in buds or branches from the same tree. This 
is true of the Banks and the Collamer apples, which have originated 
from the Gravenstein and Twenty Ounce varieties, respectively, by 
variations in single branches of their parent trees. In them, the 
usual narrow red stripes of their parents are broadened so as to 
much more completely cover the fruit. 

In two other cases that have apparently arisen from these same 
varieties by variations in the buds used in nursery propagation, these 
stripes are further broadened into practically solid red colors. These 
aie the Hitchings, and the Bed Gravenstein from an island in Puget 
Sound, reported by Beach. 1 The origin of Gano from Ben Davis 
may fie a similar case to the latter. 

At least some of these cases also are heritable. This is true of 
the Banks, which is reported to have been widely propagated in 
Nova Scotia and to have come satisfactorily true to type in most 
cases, though not in all. The genuine Gano is well known to ba 
practically constant in its solid red colors, at least within its proper 
habitat. 

These rather striking and apparently heritable differences in color, 
some of which have certainly originated by vegetative variation, 
seem more nearly to prove the existence of genuine bud mutations, 
and the possibility of their utilization in apple improvement along 
various lines, than any other evidence we have. 

SUMMARY AND CONTENTS. 

1. In America, the apple is by far the most largely grown fruit. 
At present also the interest in it is apparently greater than ever 
before. 

2. Production, however, has not kept pace with the increase in 
planting, some data indicating that the latter recently has been at 
least three times as rapid as the former. This fact, together with 
the great expansion in capital involved, emphasizes the necessity for 
better and more thorough knowledge on the part of all connected 
with the industry and its development. 

3. This publication continues the work presented in our Annual 
Reports for 1907 to 1910, and in our Station Bulletins 91 and 100. 
The results now cover four years, and involve 18 experiments and 
3,660 trees. Those considered here are chiefly from 2,219 trees, located 
in ten experiments in as many different parts of the state. They 
involve ten soil types and 829,527 pounds of fruit. Detailed accounts 
of these experiments are given, and the results and observations of 
others also have been introduced where it seemed desirable. 

4. The various factors, both internal and environmental, that 
may influence apple production, are here enumerated, and, a principle 
or hypothesis is stated, which indicates the general conditions under 
which any factor may become important. This is a modification 
and extension of the so-called "law of the minimum," which we 
have termed the "optimum" principle. See pages 407 to 409. 

5. The development of the fundamental facts of orcharding, as 
well as the development of the best possible practice in any given 

'Beach, S. A. Rural New Yorker 1911: 263. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 507 

orchard, calls for extended use of the experimental method. The 
principal rules and precautions that attend the application of this 
method to orcharding are staled. Pages 409 to HI. 

6. The value of plant-food applications i<> apple trees has been 
questioned. In some situations and iu the presence of oilier limiters, 
this attitude is undoubtedly correct. We find, however, that the 
annual plant-food draft of a vigorous and productive apple orchard 
is actually greater for every eh menl than thai of a twenty-five bushel 
crop of wheal. We also find thai very important increases in orchard 
yields may often be obtained with proper applications of plant food. 
These increases, in some cases in our experiments, have been from 
four to thirteen times the yields produced on similar adjacent un- 
fertilized plots. The accompanying net gains have been as high 
as f 267 per acre in a single year. Pages 421 and 465 to 467 and Table 
XXXIII with context. 

7. The ability of trees to maintain themselves over considerable 
periods without apparent need of extra fertilization is probably not 
due to their reputed deep-rooting habit nor to other reasons com- 
monly advanced. It seems to be due, however, to their relatively 
natural demand, their long season of root activity, and the return 
of most of the plant food of the leaves to the soil. The carbon dioxid 
and other products developed in the decay of humus and cover crops 
are also doubtless an important adjunct. See Table XXVII and 
discussion following, pages 447 to 449. 

8. The Mineral Composition of Apples. — (a) A fairly exact knowl- 
edge of the composition of all parts of the crop with which one is 
working is evidently desirable. This we have worked out for the 
fruit and vegetative parts of apples. For the results and method 
of obtaining them, see pages 421 to 436, and especially Table XYIII. 

(b). In studying the data on composition, some interesting 
variations appeared, which showed evident migration of min- 
eral elements from the older parts to the younger and from 
vegetative parts to the fruit. Young twigs and roots, for 
example, are from 2 to 5 times as rich in minerals as the older 
w T ood. Also in crop-years the ash-composition of leaves is 
much lower than in off years, thus indicating a considerable 
transfer of materials to the fruit. Pages 432 to 433. 

9. The annual weight of wood, leaves, and fruit produced by a 
mature apple tree is estimated, and the present bases for such 
estimates are presented. For average conditions in good orchards, 
these weights appear to be about 100 pounds each of wood and 
green leaves and 14 bushels of apples per tree. Pages 436 to 4:'.!). 

10. The Annual Plant-Food Draff of Mature Apple Trees.— Var- 
ious attempts, both in America and Germany, have been made to 
answer this question. The ossein ial features of their estimates are 
presented, and a new approximation, based upon the composition 
tables and annual weights derived above, has been computed and 
is presented herewith. See pages 439 to 449, and especially Table 
XXVI with context. 

11. Along with the determination of the amounts of nutrients 
found in the apple plant, we have brought together the principal 
facts and ideas now held concerning the special functions and effects 



508 ANNUAL REPORT OP Off. Doc. 

of these nutrients. This knowlege has necessarily been derived from 
plants in general, hence it has general application to the apple as 
to any other plant. Such special applications as are evident at the 
present time, however, have been indicated. Pages 449 to 454. 

12. The toxicity of the salts of certain bases, including many 
of the mineral nutrients, is apparently worthy of much more atten- 
tion in connection with crop-fertilization than it lias received here- 
tofore. Certain anomalous effects of fertilizers upon fruits, ob- 
served in our experiments and elsewhere, are explainable on this 
hypothesis of basic toxicity and its neutralization, and apparently 
in no other way. Further experiments are in pi ogress more fully 
to determine the facts. Pages 454-455, and 461 to 4(>5. 

13. If the above hypothesis proves finally to be correct, it will 
make clear the cause and prevention of the apparently new physio- 
logic disease of apple trees, noted by us in our last annual report. 
It should do this also for similar injuries to fruits that have been 
observed elsewhere; and by indicating how to eliminate the possible 
injuries, it should enable us to furnish the most favorable conditions 
for obtaining maximum effects from fertilizer applications, in apples 
as well as other crops. 

14. The results of plant-food applications upon apple produe 
tion, that have been obtained in our experiments, are given in detail 
on pages 455 to 467. 

(a) These experiments show, in general, that the influence of 
nitrogen upon yield is likely to be important, whether applied 
in the form of manure or in commercial forms. Its influence 
in our total results to date, however, is considerably reduced 
as compared with earlier returns. This is probably connected 
with the droughty conditions that have prevailed during the 
past two seasons, and with the operation of the biennial bear- 
ing habit. Present indications are that this reduction in 
influence is only temporary. See Tables XXVIII to XXXII 
and context. 

(b) The precautions in the use of nitrogen, stated in our 
earlier publications, have not been modified. These involve 
the time of application and the relation of nitrogen to color. If 
applied in soluble form, especially on leachy soils, probably 
the best time of application is somewhat after petal-fall, when 
the stored food is exhausted and the need is greatest. Also, 
on account of its indirect reduction-effect upon color, nitrogen 
can be used most freely on the earlier soils, or in localities with 
long growing seasons, or on varieties without red fruit. Nitro- 
gen may be secured in cover crops, manure, or in commercial 
forms, probably without material difference in effect, if suf- 
ficient lime is present. 

(c) The influence upon yield of phosphates and potash, when 
used in connection with other fertilizer materials, is becoming 
much more distinct and important. Their influence on size, 
especially that of potash, is also becoming more evident. Their 
influence when used alone, however, and also their effects on 
color, are practically nothing as yet. See Tables XXVIII 
to XXX 1 1 and context. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 509 

(d) "Floats, 1 " when applied alone, continues to show no im- 
portant beneficial effects. The same is true of lime in the 
older set of experiments, though rather marked benefits have 
appeared from it in our later set. An explanation for this is 
suggested. See Table XXX II and following pages as far as 
page 4G5. 

(e) Our present observations indicate that there is a relation 
between certain kinds of fertilization and injury from fire- 
blight, though the relation has not yet appeared in all experi- 
ments. In general, the injury from blight has been greatest 
on the plots receiving fertilizers that resulted in the most 
vigorous and succulent growth. This was especially true of 
stable manure. Page 407.. 

(f) Our general fertilizer recommendation for bearing apple 
trees in this state, in amounts per acre, remains as previously 
stated, viz., 30 pounds of actual nitrogen, 50 to 00 pounds 
of actual P 2 5 , and 50 pounds of actual K 2 (). This may be 
supplemented with cover crops, through which all the nitro- 
gen may be obtained, and alternated with stable manure at 
the rate of about 10 tons per acre, at least every third or 
fourth year. 

15. Results from orchard fertilization in Massachusetts are similar 
to those obtained by us. They are given in Table XXXIV and 
context. 

16. Attempts to feed trees directly, by means of injections, have 
thus far proved of little avail. The work on this point has been 
done elsewhere, and it is summarized on pages 40!) and 470. 

17. A bibliography of reports and papers bearing upon orchard 
fertilization and tree injections is given on pages 471 to 474. 

IS. The influence of various cultural methods upon apple pro- 
duction, as indicated by our experiments, is given on pages 475 to 486. 
In general these experiments show that: 

(a) When used without any fertilization, rather marked dif- 
ferences appear between the four cultural methods compared. 
Tables XXXV to XXXVII and discussion following. 

(b) When used in combination with fertilization, — either ma- 
nure or a complete commercial fertilizer, — these differences are 
greatly reduced and in some cases reversed. See Table 
XXXVIII and context. 

(c) In the younger orchards, in which the bearing habit is 
not fully established, the mulch method has thus far proved 
best in most respects. The apparent influence in hastening 
beating noted before has thus been maintained. See pages 
476 to 479 and 484 to 486. 

(d) In the mature orchard, without fertilization, the tillage- 
and-covercrop method has thus far proved much superior to 
mulching. When fertilizers are added, however, the situation 
is now reversed. This is largely due to a remarkable, con- 
secutive increase in bearing that has occurred on the latter 
plots. It suggests that proper fertilization may largely take 
the place of tillage, in some cases at least ; and, in the presence 
of sufficient available plant food, undisturbed root-systems 
may be more efficient than those annually pruned by current 
methods of tillage, 



510 ANNUAL REPORT OF Off. Doc. 

19. As previously noted, the lower moisture-draft of legumes, to- 
gether with their favorable nitrogen relations, makes them especially 
valuable in orchards as covercrops, intercrops, or permanent covers. 
We have observed quite marked differences, however, in the moisture 
draft of different legumes, the more hairy forms being least ex- 
haustive, and hence most valuable as permanent covers. See page 
480. 

20. The detailed effects of manure in conjunction with different 
cultural methods are given in Tables XXXIX and XL and their 
contexts. In general, their addition has been beneficial. ' 

21. A study of the distribution of feeding-roots in apple trees is 
presented on pages 487 and 488. Under our conditions, the root- 
feeding zone is relatively shallow. The roots were studied in 28 
trees of 10 varieties on 10 different soil types and under two cultural 
methods. The maximum numbers of feeding roots, on the average, 
ranged from 2.7 to 12 inches. 

22. A bibliography to papers on cultural methods in orchards, 
and allied subjects, is given on pages 488 to 492. 

23. Variation and heredity as factors in apple production are 
discussed on pages 493 to 499. 

(a) The utilization of the forces of variation and heredity in 
the improvement of apples is evidently desirable, though not 
yet entirely proved to be practicable. If the effort toward 
improvement is made by way of the seed, an important diffi- 
culty appears in the extremely heterozygous condition of the 
gametes. If the effort is made by way of cion-selection, we 
find ourselves dealing with "clons," which are essentially iden- 
tical or at least analogous with "pure lines," and in which 
the possibility of important progress by means of selection 
is yet uncertain. 

(b) Along the line of cion-selection, however, we have found 
that important variations do exist between trees of the same 
variety under similar conditions. Data from experiments 
elsewhere covering considerable periods show that certain 
trees have produced from 65.5 to 315.5 per cent, more fruit 
than adjacent trees under apparently identical conditions. 
(Tables XLII to XLIV). In our own experiments, twenty 
comparisons, each involving 10 high yielding versus 10 low 
yielding trees, show an average difference in yield during three 
years of over 320 per cent. In other words, 20 groups of 
trees during three years have produced over 4 1-5 times as much 
fruit as 20 adjacent groups under apparently identical con- 
ditions and treatment. Table XLV and context. 

(c) The exact nature and the heritability of these variations are 
not fully understood. Such evidence as we have at present 
is rather indicative of non-inheritance, though the case is not 
entirely settled, and some things point toward final success. 
Pages 496 to 499, and 505 and 506. 

24. A brief bibliography on cion-selection and other phases of 
apple breeding is given on pages 499-500. 

25. Factors influencing size in apples are considered in pages 
500 to 503, and in Tables XXX to XXXII, XXXV to XXXVII, 
and XL. 



No. 20. THE PENNSYLVANIA STATE COLLEGE. 511 

(a) Iii general, we find that the size of the crop on the tree 
has no influence on the size of the fruit, until the former 
passes a certain critical point. From correlation curves, 
shown in figures 23 to 26, this point is not lower than 1200 to 
1500 apples per tree, on trees of only moderate size and age. 
Above this critical point, however, crop-size is probably the 
dominant influence on size of fruit. 

(b) Below the critical point, other factors, — such as moisture- 
supply, cultural methods, fertilization (especially with manure 
and potash), temperature and length of growing season, and 
probably pollination and number of seeds per fruit — all these 
may exert an important influence on fruit size. When work- 
ing in conjunction, these latter factors may also materially 
raise the point at which crop size becomes operative. Pages 
501-502. 

(c) According to this, if one thins an apple tree of even moder- 
ate size before the number of fruits reaches 1400 or more, 
the size of the remaining fruit will hardly be increased, and 
hence the net effect of the thinning will be a reduction in total 
weight of fruit, at least for that year. Exceptions may occur 
with varieties of extra large size, or in seasons or locations 
that are exceptionally dry. 

20. Factors influencing color in apples are considered in pages 
503 to 506, and also in the tables indicated in section 25 above. 

(a) The yellow colors in apples are independent of light and 
of nearly all other environmental conditions. The red colors, 
however, are primarily dependent upon sunlight, and espec- 
ially upon the amount received during the later stages of 
maturity. Maturity in sunlight is therefore the dominant en- 
vironmental influence in the production of color in apples. 
Hence, anything, that tends to hasten maturity, or to increase 
the amount of sunlight received, will favor color, while the 
reverse conditions will injure if. Pages 503 and 504. 

(b) Exposure of apples to sunlight after picking increased 
their redness by :*>5 per cent., while the checks in the dark and 
those exposed to electric light showed no definite increase. 

(c) Abundance of iron in the soil or iron applications have 
long been supposed to have some relation to color in apples. 
The present experimental evidence does not justify this opin- 
ion. Pages 504 and 505. 

(d) The available evidence upon fertilizers in their relation to 
color in flowers is also negative, so far as improvement is con- 
cerned. Page 505. 

(e) Get tain arsenical sprays have shown distinct improvements 
in color, especially on peaches. This is probably due to in- 
creased sunlight, following a reduction in the amount of fol- 
iage, together with some stimulative effect from mild amounts 
of the poison. Page 505. 

(f) Variation and heredity have important relations to color 
in apples, and the possibility of their utilization in its im- 
provement is apparently good. Pages 505 and 506. 

'Respectfully submitted, 
July 1, 1911. JOHN P. STEWART. 

36 



512 ANNUAL REPORT OF Off. Doc. 



PENNSYLVANIA FRUIT SOILS, AND SOIL-VARIETY ADA I' 

TAT IONS. 



By H. J. WILDER. 



CHAPTER I 

It is the purpose of this bulletin to discuss: (1) The necessity for 
careful selection of the soil for orchard purposes; (2) Soil-crop re- 
lationship as shown by experimental evidence and field observations; 
(3) The soils of Pennsylvania with reference to their main or "series" 
divisions, including brief descriptions of each and their relative pro- 
ductivity; (4) The adaptation of different varieties of apples to par- 
ticular kinds of soil, and some opportunities for orcharding on Penn- 
sylvania soils as based upon these adaptations, land prices, and 
accessibility to markets, with reference to the development of both 
farm and commercial plantings. 

THE NEED FOR SOIL SELECTION. 

The selection of the soil for orchard planting has received relatively 
little attention in the past as compared with that given to selecting 
soils for other special crops. In the production of the latter, such 
as tobacco, onions, garden and floral crops, competition has forced 
the selection of favorable soils as well as suitable conditions. The 
most successful growers have learned through experience, moreover, 
to discriminate carefully in choosing their soils. 

The general farmer has not advanced so far in the matter of select- 
ing particular soils for his crops, or stated conversely, in using his 
soils to grow only those crops which they are best adapted to pro- 
duce. This is largely due to the fact that the money returns per 
acre are much less than from special crops and, hence, it has not 
been so essential to select soils with as much care as for special crops. 
Even so, in the eastern United States there are many soil areas 
from which general farming has been driven because the soils were 
not adapted to such use. And this statement is not meant to include 
rough lands which have been unable to compete on account of the 
relatively heavy expense of working them. 

There is no longer any question as to Avhether orcharding is a 
specialized business. The steadily increasing demand for orchard 
products of select appearance has compelled groweis, who would 
succeed, to spray thoroughly, to maintain a well balanced wood 
growth, and to markefthe fruit in an attractive manner. 

As a result of the vast amount of orchard experience already ac- 
quired, it is apparent that some soils have given better returns than 
others. Hence, we get from many sources the prescription of "a 
deep well drained soil for successful apple growing." No one will 
question the excellence of this general rule, which is in fact just 
as applicable to other crops as to apples. But there is a tremendous 



LIBRARY OF CONGRESS 




mm „ ., 

000 929 910 5 « 



